Fill in a delivery address from your current location: how does HowBridge find your house number?
What is "Use current location to fill in address", and which government service does it use?
It is a button in the HowBridge Member Center for entering a home-delivery address in Taiwan, and behind it is the Ministry of the Interior TGOS "coordinate-to-address service". HowBridge submitted its application on 2026-10-02 (application number SO20261002009), received the approval notice on 2026-10-06, and went live on the production site the same day. After you press the button and allow browser location, the HowBridge server sends the device coordinates to TGOS to find nearby house numbers, and then calculates the distances itself; the city/county, district, postal code, and street and house number are filled in only when you press 套用 ("Use"), after which the system runs its usual house-number matching. On 2026-10-06 we ran 11 tests at 10 places in Taiwan; 9 found a house number, and each call to TGOS took about 0.1–0.7 seconds. Your location is not stored in your member data; and approval does not mean government certification or endorsement of HowBridge.
It is an aid that saves you typing and typing mistakes: it uses where you are right now to find nearby house numbers for you to choose from. It does not fill in and save automatically, and it does not track your location: your location is obtained once, and only if you press the button and agree when the browser asks. It is not government certification: what the Ministry of the Interior reviewed was HowBridge's application to use the TGOS service, not an endorsement of HowBridge's services. For now, only the website Member Center (in a computer or phone browser) has this button; the HowBridge app and the LINE official account do not have it yet. HowBridge only provides mainland China → Taiwan consolidation shipping, its only warehouses are the Shenzhen consolidation warehouse and the Taoyuan Dayuan operations warehouse, and it does not offer purchasing on your behalf.
How did HowBridge get the Ministry of the Interior TGOS coordinate-to-address service?
TGOS is the Ministry of the Interior's integrated geographic information cloud platform, managed by the Information Service Department of the Ministry of the Interior. The platform introduction states that system developers can use the "coordinate-to-address integration service"; the service list names companies and businesses among the eligible users of the coordinate-to-address service, applications are made online, and only after approval can you obtain an application ID (APPID) and an integration authentication key (APIKEY). HowBridge's application and go-live went as follows:
| Item | Details |
|---|---|
| Service applied for | Ministry of the Interior TGOS "coordinate-to-address service" (web service, GeoQueryAddr v4.0) |
| Application number | SO20261002009 |
| Application submitted | 2026-10-02 14:09, submitted after verification with the MOEA business certificate (smart card) of HowBridge Information Co., Ltd. |
| Purpose stated in the application | When a member enters a Taiwan delivery address, the device obtains the coordinates of its location, and the HowBridge server looks up the nearest house numbers for the member to confirm, reducing manual entry errors; it is called only by the HowBridge Taiwan server and is not resold or provided to third parties |
| Review result | 2026-10-06 09:45: received the TGOS platform "service review result notice": approved |
| Go-live | Midday on 2026-10-06: server side live at 12:17, Member Center button live at 12:29; the key is kept only on the HowBridge Taiwan server and is not placed in the web page |
| Related services | HowBridge also obtained approval on 2026-09-21 to use the TGOS "nationwide house-number location matching service" (used to check the address you enter), and on 2026-10-02 the "batch address matching service" |
| Usage quota | The TGOS application notes state that advanced use allows 300,000 matching queries per month, counted per calendar month |
What the TGOS platform reviewed was HowBridge's application to use the coordinate-to-address service; once approved, the platform issued an application ID and an integration authentication key so that HowBridge's server can call the service. This is not government certification or endorsement of HowBridge, and it does not mean the Ministry of the Interior has a partnership with HowBridge. Every use of "approved" on this page refers to that service-use application. The TGOS government website open-data statement also says that the license "does not grant users the standing to represent the agency in recommending, approving or endorsing their value-added derivatives" (that statement concerns the data published on the TGOS website, but the principle is the same).
The Ministry of the Interior's "Rules for Using the Nationwide House-Number Address Positioning Service" (2025-03-31 version) list several restrictions: it may not be used for purposes other than the one applied for, it does not provide integration for IPs or domains outside the Republic of China, it may not be copied or passed on for use by third parties, and continuous large numbers of queries in a short time are not allowed without authorization; the Ministry of the Interior does not guarantee that the data are correct or complete. The rules also have a "reciprocity principle": the integrating system must show the TGOS logo and a link to the TGOS website, so when the Member Center shows a query result, a TGOS logo appears next to it, and clicking it opens the TGOS website. HowBridge calls the service only from its Taiwan server and limits the number of queries each member can make.
What does the coordinate-to-address service return?
The coordinate-to-address service takes the latitude and longitude of a point and returns nearby house numbers, which is known as "reverse geocoding". The official specification lists 5 query methods, and HowBridge uses 2 of them:
| Query method | Official description | How HowBridge uses it |
|---|---|---|
PointQueryNearAddrByBuffer | Looks up the nearest house number from a point coordinate, with a search range (in meters) that can be set to extend outward | Main query: the search radius is set from the location accuracy reported by your device |
PointQueryNearAddr | Looks up the nearest house-number point from a point coordinate | Used once more only when nothing is found within the radius |
PointQueryAddr | Looks up house-number points from a point coordinate plus a search range | Not used (HowBridge uses PointQueryNearAddrByBuffer instead, which lets you set the range and returns the nearest house number) |
LineQueryAddr、PolygonQueryAddr | Looks up house numbers within a line or area | Not used |
What fields does each house number include?
In the 2026-10-06 tests, each result had the full house number (FULL_ADDR), split into fields for city/county, township or district, village, neighborhood, road section, lane, alley and number, plus the latitude and longitude of the house-number point and the distance. For example, a query at the coordinates of Taipei 101 returned 臺北市信義區西村里8鄰信義路五段7號, about 43 meters away.
Where do house-number points come from?
A 2022 report by the Department of Statistics, Ministry of the Interior explains that house-number points are maintained by household registration office staff on the Ministry of the Interior's system and then transferred to TGOS. Statistics on the Government Open Data Platform show that in ROC year 114 (2025), 22 cities and counties marked a total of 10,698,546 house-number locations; Taipei City, New Taipei City, Taichung City and Yilan County update monthly and the other 18 cities and counties update irregularly; 163,251 were changed during the same year. So a newly assigned house number may not have a point yet.
What is not included?
The result has no floor and no postal code. So after the address is filled in, you need to add the floor yourself; the 3-digit postal code on the form is filled in from the district. The coordinate system is WGS84 (EPSG:4326), the latitude and longitude used by phone and browser location.
After you press "Use current location to fill in address", how does the system find the house number?
From pressing the button to filling in the form, the order is as follows. The whole flow starts when you press the button, and you must select a result before it is filled in; the system does not obtain your location in the background:
| Step | What happens | Notes |
|---|---|---|
| 1 | The browser asks whether to allow use of your location | It continues only if you press "Allow"; if you press "Block" it shows "無法取得位置：請允許瀏覽器使用定位，或直接手動輸入地址" ("Unable to get your location: please allow the browser to use location, or enter the address manually") |
| 2 | The browser obtains the coordinates and accuracy once | Only once, with no continuous tracking; it waits at most 12 seconds |
| 3 | The HowBridge server first checks whether you are in or around Taiwan | If the coordinates are outside the latitude and longitude range around Taiwan (for example Shenzhen), it directly shows "您目前的位置不在台灣，請手動輸入台灣收件地址" ("Your current location is not in Taiwan; please enter a Taiwan delivery address manually") and nothing is sent to TGOS; the range is a rough box from 21.5–26.5 degrees north and 118–122.5 degrees east, a few places on the Fujian coast also fall inside the box, and those are queried but usually show no house number found |
| 4 | Decide the search radius | The accuracy reported by the device multiplied by 1.5, with a minimum of 30 meters and a maximum of 200 meters; if the browser gives no accuracy, 60 meters is used |
| 5 | Call TGOS to find house numbers within the radius | The coordinates are first rounded to 4 decimal places (about 10 meters) before the query |
| 6 | If nothing is found within the radius, find the nearest one | The nearest house number is listed only if it is within 500 meters; any farther is unlikely to be where you are, and it shows "附近查無門牌，請手動輸入地址" ("No house number found nearby; please enter the address manually") |
| 7 | List candidate house numbers with distances | Nearest first, at most 5; the screen states that the data source is the Ministry of the Interior TGOS coordinate-to-address service and shows the TGOS logo, which opens the TGOS website when clicked |
| 8 | You press 套用 ("Use") to fill it in | The city/county, district (the postal code follows) and street and house number are filled in, without the village and neighborhood; the system then checks this address as usual against Chunghwa Post and TGOS house-number matching |
Why does the search radius change with accuracy?
Phones are usually more accurate outdoors, and the error grows indoors or between tall buildings. The browser tells the web page "this location is accurate to about how many meters", and the W3C Geolocation specification defines this number as the radius at the 95% confidence level. HowBridge enlarges it 1.5 times to use as the search radius: when the location is accurate it looks only at house numbers right around you, and when it is rough the range is widened, but never beyond 200 meters, to avoid listing addresses that are too far away.
What happens if TGOS cannot be reached?
Each call to TGOS waits at most 4 seconds (two calls are made when a second look-up is needed). If 3 timeouts, connection failures, rate limits, server errors or access denials add up across the whole site within 15 minutes, the system pauses calls for 5 minutes; during that time the button shows "目前無法依位置查詢門牌，請手動輸入地址" ("House numbers cannot be looked up by location right now; please enter the address manually"). Entering an address manually is not affected at all.
Why must I select one myself?
The nearest house number is not necessarily yours: a large building may have several house numbers, and a location in an alley may be off by a neighboring building. So the system only lists candidates and distances, and you decide whether it is the right address; you can still edit it after it is filled in.
Test results: what do you find when you press it around Taiwan?
On 2026-10-06 we called the TGOS coordinate-to-address service directly from the HowBridge server, using coordinates near public landmarks, with no member locations involved. We ran 11 tests at 10 places in Taiwan (Taipei 101 was tested at two accuracy levels), and 9 found a house number; each call to TGOS took 0.11–0.67 seconds (1.38 seconds for the first connection), and when nothing is found within the radius and a second look-up is needed, two calls are made:
| Test location (coordinate accuracy) | Search radius | Result | Notes |
|---|---|---|---|
| Taipei 101 (20 meters) | 30 meters | Nothing within the radius → nearest 信義路五段7號, 43 meters | House-number points are sparse around large buildings, so the "find the nearest one" step fills the gap |
| Taipei 101 (150 meters) | 200 meters | 信義路五段7號, 43 meters | With coarser location the radius is enlarged, and it is found in one go |
| Rural settlement in Dayuan District, Taoyuan City (not provided) | 60 meters | 倒厝子72號, 44 meters | House numbers in settlements without road names can also be found |
| Near Taoyuan International Airport Terminal 1 (30 meters) | 45 meters | Nothing within the radius → nearest 航站南路11號, 63 meters | Filled in by the "find the nearest one" step |
| Near 85 Sky Tower (Kaohsiung), Lingya District, Kaohsiung City (25 meters) | 38 meters | 自強三路3號, 26 meters | |
| Near Hualien Railway Station (40 meters) | 60 meters | 國聯一路100號, 51 meters | |
| Jincheng Township, Kinmen County (40 meters) | 60 meters | 中興路22巷11號, 3 meters | Outlying islands can also be found |
| Magong City, Penghu County (40 meters) | 60 meters | Nothing within the radius → nearest 西文澳104號之14, 67 meters | House numbers with a sub-number suffix are also returned correctly |
| Orchid Island (Lanyu), Taitung County (60 meters) | 90 meters | No result | There are no house-number points near this test point, and not even a nearest one was found |
| Near the main peak of Yushan (Jade Mountain) (150 meters) | 200 meters | Xinyi Township, Nantou County 觀高山1號, 66 meters | House numbers in the mountains also have points |
| At sea in the Taiwan Strait (not provided) | 60 meters | No result | There are no house numbers at sea |
| Shenzhen, Guangdong, China (not provided) | — | Not in Taiwan, no query sent | Only Taiwan delivery addresses are handled |
First, most places return only 1 house number, so the screen usually shows a single candidate; distances were 3–67 meters. Second, "find the nearest one" is essential: in 5 of the 11 tests nothing was found within the radius, and in 3 of them this step found one. Third, when nothing is found, enter it manually: at sea and at some remote places there are no house-number points, and the system simply asks you to type the address, rather than forcing a faraway address on you.
How do members fill in a delivery address from their current location?
No separate application or setup is needed; it works best when you are at the delivery location:
1Open Add recipient
Go to Recipients in the Member Center, press 新增收件人 ("Add recipient"), and choose 宅配地址 ("Home delivery address"). The button is also there when you edit an existing home-delivery recipient.
2Press <span class="alg-lit">使用目前位置帶入地址</span> ("Use current location to fill in address")
The button is above the city/county field. When the browser asks, choose "Allow"; your location is obtained only this one time.
3Confirm the candidate house number
The screen lists nearby house numbers with distances, for example "距離約 43 公尺" ("about 43 meters away"). If it is your address, press 套用 ("Use"); if not, press 收起 ("Collapse") and enter it manually.
4Add the floor, confirm and save
The filled-in address goes only as far as the house number, so add the floor yourself if there is one. The system then matches the house number as usual; when you see "已比對到門牌地址" ("House-number address matched") or "郵政標準地址" ("Postal standard address"), it means the way you wrote it matches official data; fill in the name and phone number and save.
Where does my location go? Is it stored?
Under Article 2 of the Personal Data Protection Act (Taiwan), personal data includes "other data by which a person can be identified directly or indirectly". A 2026-06-16 interpretation by the Personal Data Protection Commission Preparatory Office (the original case concerned ambulance location points) also explains that real-time latitude and longitude is still personal data if it can be restored by certain methods to identify a specific person. The W3C specification requires explicit user consent before location is obtained. HowBridge's approach:
| Item | What HowBridge does |
|---|---|
| When location is obtained | Only when you press the button and agree when the browser asks, and only once; there is no continuous location in the background. Other sites' content embedded in a 0523.tw page (for example an external frame) cannot use location, under the browser permissions policy (Permissions-Policy) that HowBridge sets |
| What is sent to the HowBridge server | The latitude and longitude reported by the device (at original precision) and the location accuracy. The request is sent under your login identity, used only to limit the number of uses; the coordinates are not saved together with your account |
| What is sent to the Ministry of the Interior TGOS | Latitude and longitude rounded to about 10 meters, and the search radius; no name, phone number or account |
| Whether it is stored in member data | No. The coordinates are not written to your member or recipient data; only an address that you press "Use" for and then save becomes recipient data, just like one you type in manually |
| Query result cache | Not cached: every time, TGOS is queried in real time and the house numbers found are only shown on screen; only an address you click "套用" ("Use") on and save is kept |
| System logs | System logs do not record coordinates, only the reason for an error |
| Usage limits | Each member can make at most 20 uses per minute and 100 uses within 24 hours, to prevent abuse |
| Privacy policy | Updated on 2026-10-06 to version 2.2.0, with a description of this feature added in section 4.1; see the Privacy Policy |
What are the limits of filling in an address from your current location?
This button saves you typing, but there are a few things to know:
Not accurate if you are not at the delivery location
It finds house numbers at where you are right now. If you are at the office but need to enter your home address, just type it in manually.
Location itself has error
Indoors, in basements and between tall buildings, location error is larger and may give a neighboring or opposite building's house number. Always check the candidate address carefully before pressing Use.
No floor
The house number TGOS returns has no floor, so after it is filled in you need to add "floor N" or the room number yourself.
Only in the website Member Center for now
It works when you open the Member Center in a computer or phone browser; the HowBridge iPhone and Android apps and the LINE official account do not have this button yet, and an app version is planned separately. If a browser or an app's built-in browser does not support location, the button does not appear; if you block location permission it shows "無法取得位置：請允許瀏覽器使用定位，或直接手動輸入地址" ("Unable to get your location: please allow the browser to use location, or enter the address manually"); if location times out it shows "目前無法依位置查詢門牌，請手動輸入地址" ("House numbers cannot be looked up by location right now; please enter the address manually"); in that case please enter it manually.
Taiwan addresses only
No query is made when the coordinates are outside the latitude and longitude range around Taiwan; the range is a rough box, a few places on the Fujian coast also fall inside it, and in that case a query is sent but usually shows "附近查無門牌，請手動輸入地址" ("No house number found nearby; please enter the address manually"). HowBridge only provides mainland China → Taiwan consolidation shipping, and delivery addresses are all in Taiwan.
Even official data is not guaranteed to be fully correct
The usage rules state that the Ministry of the Interior does not guarantee that the data are correct or complete; the Department of Statistics, Ministry of the Interior's 2022 report also mentions that the nationwide house-number location dataset contains some wrongly split addresses. This is also why house-number matching runs again after the address is filled in, and why you confirm it yourself.
Finding a house number does not guarantee delivery
House-number data only confirm that this house number exists. You still need to confirm the recipient's name, phone number, building-management-office receiving and so on yourself, and delivery is the responsibility of the courier that actually carries the parcel.
How accurate is phone location? What research can we refer to?
The studies and reports below provide background and are not about HowBridge; most of the figures come from other countries or specific experimental settings and cannot be applied directly to your phone:
- How accurate is phone location: in a Stanford online GPS course, more than a thousand students measured with their own phones, with an average accuracy of 4.9 meters under open sky; the US government GPS website also gives 4.9 meters, but says it gets worse near buildings, bridges and trees. A measurement of an iPhone 6 beside buildings on a university campus averaged 7–13 meters.
- Different positioning methods differ greatly: a 2009 comparison of three iPhone positioning methods found a median error of 8 meters for A-GPS, 74 meters for Wi-Fi and 600 meters for cell towers. On a computer or indoors with only Wi-Fi, the error can reach tens of meters or more.
- How to read the accuracy a browser reports: the W3C Geolocation specification states that accuracy is the radius at the 95% confidence level (in meters), and that explicit user consent is needed before location is obtained; it also recommends that recipients discard the location information once they have used it, unless the user explicitly allows it to be kept.
- House-number points are more accurate than road-segment estimates: in a study of 3,000 addresses in New York State, with street interpolation 95% of urban errors were within 152 meters; using parcel points reduced that to 21 meters. An Iowa study also found a median error of 39 meters with E911 house-number points and 90 meters with street-data matching.
- Reverse geocoding makes mistakes and also carries privacy risk: a Vienna study compared seven free reverse geocoding services and found that only 0–23% of the returned addresses were correct, and that when the results were checked against a free phone directory, 68% of people could be identified.
- Wrong addresses have a visible cost: a US Postal Service Inspector General report found that 4.3% of mail could not be delivered as addressed in both FY2013 and FY2014, with handling costs of nearly US$1.5 billion a year; the 2022 report of the Department of Statistics, Ministry of the Interior (Taiwan) also mentions that the nationwide house-number location dataset contains some wrongly split addresses.
What are the common terms for filling in an address from your current location?
- TGOS
- The Ministry of the Interior's integrated geographic information cloud platform, which provides web services such as house-number location matching and coordinate-to-address lookup; companies and businesses must apply and pass review before they can use it.
- Coordinate-to-address service (GeoQueryAddr)
- A TGOS web service: given the latitude and longitude of a point, it returns nearby house numbers and the coordinates of their house-number points; HowBridge uses version 4.0.
- Reverse geocoding
- Finding an address from latitude and longitude; the opposite, finding latitude and longitude from an address, is called geocoding.
- Latitude and longitude (WGS84)
- The coordinate system used by phone and browser location, with code EPSG:4326; latitude is the north-south position and longitude is the east-west position.
- Location accuracy
- How many meters the browser reports this location is accurate to; HowBridge uses it to decide the search radius.
- Search radius
- The range around your position in which house numbers are looked for; HowBridge sets it to 1.5 times the accuracy, between 30 and 200 meters.
- House-number point
- The coordinate that represents each house number on the map, built by the household registration authorities; reverse geocoding finds the nearest of these points.
- Browser location permission
- Before a web page can get your location, the browser asks you first; you can allow or block it, and change it later in the browser settings.
What are the sources and the scope of verification?
The sources below were consulted on 2026-10-06; document dates and consultation dates are shown separately, and dates not stated are not made up.
Primary government and official sources
- Ministry of the Interior TGOS: coordinate-to-address service WSGeoQueryAddr40 web service description | Document date: not stated; the service description reads "Coordinate-to-address service: after authorization is verified, matches house-number locations using point, line or area + search range"; the WSDL lists 5 operations: PointQueryAddr ("queries house-number locations using point coordinates + search range", with oBuffer in meters), PointQueryNearAddr and PointQueryNearAddrByBuffer ("queries the nearest house-number location using point coordinates"), LineQueryAddr and PolygonQueryAddr; oSRS can be EPSG:4326, 3825, 3826, 3827 or 3828; it returns JSON or XML; an APPId and an APIKey obtained after a successful application must be passed as a pair.
- Ministry of the Interior TGOS: nationwide house-number address positioning service (application notes and service list) | Document date: not stated; "Advanced use (government agencies, corporate bodies, academic units, industry)" applies to the "nationwide house-number address positioning service, coordinate-to-address service ..."; provides 300,000 matching queries per month (counted per calendar month); "apply online, and after passing review you can obtain an APPID and APIKEY". Service list: "coordinate-to-address service / integrated as a web service, supports input of point, line or area coordinates and a search range ... eligible users: government agencies, public enterprises, academic and corporate bodies, companies and businesses". The footer reads "Information Service Department, Ministry of the Interior, all rights reserved".
- Ministry of the Interior rules for using the nationwide house-number address positioning service | Document date: 2025-03-31; file in the TGOS download area (file name 1140331). The service is "provided free of charge to all sectors" and "controlled by API KEY and registered IP / Domain"; eligibility includes "private enterprises legally registered in the Republic of China, excluding funding from China, Hong Kong and Macau". Usage restrictions: "may not be used for purposes other than the application purpose"; "integration from IPs/Domains outside the Republic of China is not provided"; "may not, on the grounds of added or improved data, be copied or handed over for use by third parties"; "without authorization, large numbers of address matching queries may not be made continuously in a short time"; "this agency does not guarantee that the content of the data is correct or complete"; violators have their service terminated and "for twelve months, no service application from that unit will be accepted". Reciprocity principle: the integrating system "must add the relevant logo and website link of this service".
- Ministry of the Interior TGOS: privacy policy of the integrated geographic information cloud platform | Document date: not stated; "Personal data file name: "Integrated geographic information cloud platform". Holding agency: Information Service Department, Ministry of the Interior", confirming that TGOS is under the Information Service Department of the Ministry of the Interior.
- Ministry of the Interior TGOS: platform introduction | Document date: not stated; "TGOS provides an online address-to-coordinate service ... for system developers, it also provides an integration service for address-to-coordinate or coordinate-to-address."
- Ministry of the Interior TGOS: government website open-data statement | Document date: not stated; "The license of this website does not grant users the standing to represent this agency in recommending, approving or endorsing their value-added derivatives." This supports that an article must not claim government certification or endorsement (the statement applies to the data and materials published on the website).
- Principles for unified collection and supply of national land geographic information | Document date: 2013-02-18; issued by letter Tai-Nei-Zi No. 1020073268 on 2013-02-18. It defines "authorized service: a network map-data integration service for which, after the competent authority registers the service information on the TGOS platform, use of the service requires an application by the user, and after review and approval by the competent authority or its authorized party, the service URL is provided and the service management rules must be followed."
- Government Open Data Platform: total number of house-number location records by city and county, ROC year 114 (Information Service Department, Ministry of the Interior) | Document date: 2026-06-09; "Statistics on the total number of house-number location records marked by each city and county in ROC year 114, with information on which cities and counties have joined the Ministry's system and how often data are updated." The CSV covers 22 cities and counties, totaling 10,698,546 records; the 4 cities and counties Taipei City, New Taipei City, Taichung City and Yilan County update "monthly", and the other 18 update "irregularly". The date is the date it was published.
- Government Open Data Platform: total number of changed house-number location records by city and county, ROC year 114 (Information Service Department, Ministry of the Interior) | Document date: 2026-06-09; "Statistics on the total number of changed house-number location records marked by each city and county in ROC year 114." The CSV totals 163,251 changes across 22 cities and counties, with New Taipei City the most at 27,327; it shows that house numbers change every year, and that members still need to confirm the filled-in address themselves.
- Government Open Data Platform: house-number usage count statistics (Information Service Department, Ministry of the Interior) | Document date: 2026-06-22; "provides usage count statistics for the house-number lookup function of the TGOS geographic information cloud service"; ROC year 111: 313,248,677 times, year 112: 275,879,705 times, year 113: 140,038,355 times, year 114: 98,210,746 times.
- Department of Statistics, Ministry of the Interior: Construction, Maintenance and Application of Address Geocoding | Document date: 2022-12-01; 2022-12, that is December 2022 (the original gives only the month, and day 01 is a placeholder). "The point data of current house-number addresses are maintained by household registration office staff on the point system at the Ministry of the Interior's information center, and then transferred to the "Geographic Information Cloud Platform (TGOS)" ... coordinate points use TWD97 2-degree zone projected coordinate values"; address matching rates "are lowest for Taipower at 88.91% ... and highest for household registration data at 99.59%"; reasons for difficult matching include "inconsistent storage formats, house-number changes, variant characters and rare characters".
- Department of Household Registration, Ministry of the Interior: house-number assignment, household registration application guide | Document date: not stated; applicants for house-number assignment are "the building owner / manager / current resident / constructor"; "where the originally assigned house-number plate has fallen off, been lost or damaged beyond use, a replacement or exchange must be applied for." It explains that house numbers are assigned by household registration authorities, and that a new building not yet assigned a number may not be found.
- Satellite Geodetic Data Processing Center, Department of Land Administration, Ministry of the Interior: establishment of the national coordinate system | Document date: not stated; "the new national coordinate system is named the 1997 Taiwan Datum (TWD97)"; reference ellipsoid GRS80 "semi-major axis a=6378137 meters, flattening f=1/298.257222101"; the main island of Taiwan uses "transverse Mercator projection in 2-degree longitude zones, with the central meridian at 121 degrees east, the projection origin shifted 250,000 meters west, and a scale factor of 0.9999 on the central meridian"; for Penghu, Kinmen and Matsu the central meridian is 119 degrees east.
- EPSG Geodetic Parameter Registry: EPSG:4326 WGS 84 | Document date: 2022-11-29; "Name: WGS 84" "Code: 4326" "Datum: World Geodetic System 1984 ensemble"; the date is the Revision Date.
- EPSG Geodetic Parameter Registry: EPSG:3826 TWD97 / TM2 zone 121 | Document date: 2008-08-11; "Name: TWD97 / TM2 zone 121" "Base CRS: TWD97" "Except for cadastral use, replaces TWD67 / TM2 zone 121 (CRS code 3828)." The information source is the National Land Surveying and Mapping Center (NLSC); the date is the Revision Date.
- Personal Data Protection Act, Article 2 | Document date: 2025-11-11; personal data "refers to a natural person's name, ... contact information, financial status, social activities and other data by which that person can be identified directly or indirectly"; "collection: obtaining personal data by any means". The date is the latest amendment date of the Act (amended 2025-11-11, with the effective date of some articles not yet set).
- Enforcement Rules of the Personal Data Protection Act, Article 3 | Document date: not stated; "identifiable indirectly means that the public or non-public agency holding the data cannot identify the specific individual from that data alone, and can do so only by comparing, combining or linking it with other data."
- Personal Data Protection Act, Article 8 | Document date: 2025-11-11; when collecting under Article 19, the party "must clearly inform the data subject" of the agency name, the purpose of collection, the categories of personal data, "the period, area, recipients and manner of use", the data subject's rights, and "the effect on the data subject's rights and interests of not providing personal data, where the data subject is free to choose whether to provide it".
- Personal Data Protection Act, Article 19 | Document date: 2025-11-11; a non-public agency collecting or processing personal data "must have a specific purpose" and meet one of the listed conditions, for example "has a contractual or quasi-contractual relationship with the data subject and has taken appropriate security measures" or "has the data subject's consent".
- Personal Data Protection Act, Article 20 | Document date: 2025-11-11; "a non-public agency's use of personal data ... must be within the scope necessary for the specific purpose of collection." Coordinates may only be used to look up house numbers and fill in the address.
- Personal Data Protection Commission Preparatory Office letter Ge-Zi-Chou-Fa-Zi No. 1150001176 of 115.06.16 (reproduced by the Taipei City Laws and Regulations Database) | Document date: 2026-06-16; "if personal data, after processing ... can still objectively be restored to indirectly identify the data subject, then regardless of how easy or difficult the restoring method is ... it is still personal data"; "real-time geographic location information (such as latitude and longitude, or information on being near an intersection after conversion), if it can be restored by certain methods to directly or indirectly identify a specific person, is still personal data." The original case concerned ambulance location points.
- National Development Council letter Fa-Fa-Zi No. 1072002039 of 107.11.07 (reproduced by the Taipei City Laws and Regulations Database) | Document date: 2018-11-07; collection of "location information" for the 119 emergency telephone line rests on Article 15 of the Personal Data Protection Act, "performing statutory duties", "but must still comply with the principle of proportionality", and cites Article 5, "must not exceed the scope necessary for the specific purpose". It shows that phone location information is treated as personal data (this case concerned a public agency).
- W3C Geolocation (Candidate Recommendation Snapshot) | Document date: 2026-03-26; it became a W3C Recommendation on 2022-09-01, and "In March 2026, the specification returned to Candidate Recommendation". "requires express permission from an end-user before any location data is shared"; in a non-secure context it calls back with PERMISSION_DENIED, "only available in HTTPS"; location is provided in WGS84, and accuracy is "95% confidence level in meters"; non-normative advice: "Recipients ought to dispose of location information once that task is completed, unless expressly permitted to retain it by the user."
- W3C Permissions Policy (Working Draft) | Document date: 2026-09-22; the example "Permissions-Policy : fullscreen=(), geolocation=()" disables that feature in all documents; "Geolocation is disabled by default in all cross-origin frames."; the Geolocation specification states that its default allowlist is 'self'.
- Regulations Governing Customs Clearance of Air Express Cargo, Article 18 | Document date: 2026-02-23; "where an express carrier declares in the name of the holder of the imported goods, except for documents it must declare the consignee's name and address ... where the consignee is an individual, it must declare the ID number, Alien Resident Certificate number or passport number." The date is the latest amendment date of these regulations.
- Regulations Governing Customs Clearance of Sea Express Cargo, Article 19 | Document date: 2026-02-23; "where a sea express carrier declares in the name of the holder of the imported goods, except for documents it must declare the consignee's name, address and unified business number"; Article 14 on combined declarations also requires "the consignee's address must be declared".
Research literature and international reports
The World's first GPS MOOC and Worldwide Laboratory using Smartphones
In a Stanford GPS online course, more than a thousand students across a hundred countries measured with their own phones: under open sky the average phone GNSS accuracy was 4.9 meters; in urban areas, accuracy was strongly correlated with the height of surrounding buildings, so the authors proposed the "urban multipath law". It shows that the same phone has larger error among tall buildings, so the search radius has to follow the accuracy the device reports and cannot be hard-coded.
GPS Accuracy
The US government's official GPS website: GPS-enabled smartphones are typically accurate to within a 4.9 m (16 ft.) radius under open sky, but get worse near buildings, bridges and trees; common error sources include signals blocked by buildings, indoor use and signals reflected off walls (multipath), and it specifically points out that many errors actually come from mapping software, for example "Incorrectly estimated street addresses".
Smartphone GPS accuracy study in an urban environment
Measured on an iPhone 6 at six survey points near buildings on a US university campus: the average horizontal accuracy was 7–13 meters, comparable to recreation-grade GPS in high-multipath environments; accuracy was better during periods of heavy Wi-Fi use. It supports the idea that "phone location in cities is often at the ten-meter level, not one meter", so the system only lists candidate house numbers and distances for the member to confirm, and does not fill them in directly.
Accuracy of iPhone Locations: A Comparison of Assisted GPS, WiFi and Cellular Positioning
Compares three positioning methods on a 3G iPhone: A-GPS median error 8 m (ten 20-minute measurements), Wi-Fi positioning median error 74 m (58 records), and cell-tower positioning median error 600 m (64 records). It shows that on a computer or indoors with only Wi-Fi or cell towers, error can reach tens to hundreds of meters, which is why the upper limit of the search radius is capped at 200 meters: when location is very rough, it is better to ask the member to type the address than to list a faraway house number.
Geolocation (W3C Candidate Recommendation Snapshot, 26 March 2026)
The browser location API specification: accuracy is the radius at the "95% confidence level" (in meters); explicit user consent is required before location is obtained; the specification also advises (not mandates) that recipients "request location only when needed, use it only for the purpose provided, and discard the location information once the task is completed, unless the user explicitly allows it to be kept". This is the design reference for this feature's accuracy×1.5 search radius and for "location is not stored in member data". HowBridge also does not cache query results.
Accuracy and privacy aspects in free online reverse geocoding services
Evaluates seven free online reverse geocoding services (including Google Maps, Bing, nominatim and ArcGIS) using Vienna crime data: depending on the accuracy level, only 0% to 23% of returned addresses were correct; and when checked against a free phone directory, 68% of possible victims could be identified by name. It shows that reverse geocoding itself makes mistakes and carries privacy risk, so this feature only lists candidate house numbers for the member to confirm, and does not store coordinates.
Positional error in automated geocoding of residential addresses
3,000 addresses in New York State: with street-centerline interpolation, 95% of addresses had an error within 152 m in urban areas, 421 m in suburban areas and 2,872 m in rural areas; with parcel points, 21 m urban, 39 m suburban and 195 m rural. It supports TGOS using "house-number points" rather than road-segment interpolation, and the design of a 500-meter fallback limit because rural error is large.
Positional accuracy of two methods of geocoding
Using GPS measurements of Iowa homes as the baseline: the median error was 62 m for TIGER street interpolation and 61 m for a commercial company; the share of town homes with error ≤100 m was 81% / 84%, but only 56% / 28% in rural areas. It shows that address points from road-segment interpolation often miss the actual doorway by tens of meters, and more so in rural areas.
Accuracy of residential geocoding in the Agricultural Health Study
Compares 5,064 Iowa addresses against rooftop coordinates as the gold standard: the median error was 39 m for E911 points and 90 m for address matching (street database); rural errors were generally larger than non-rural ones. It supports that "measured house-number points are more accurate than street estimates".
Your Location has been Shared 5,398 Times! A Field Study on Mobile App Privacy Nudging
A 22-day small field study at Carnegie Mellon University (23 participants): even with a permission-management tool already in use for a week, after receiving reminders of "how many times an app accessed your sensitive data", 95% of participants reviewed their permissions and 58% went on to restrict permissions; during the study participants restricted app access to location 74 times (27%). It shows that users care about location being accessed continuously, and this feature gets location once only when the button is pressed and does not track in the background.
Designing Usable Web Forms – Empirical Evaluation of Web Form Improvement Guidelines
An eye-tracking controlled experiment (N = 65): after improving the forms of real company websites according to 20 form guidelines, average completion time fell by 25%, 33% and 18% (three forms), and there were fewer submission attempts. It supports that "less typing and fewer format errors" make web forms faster and less often sent back (this study tested the 20 form guidelines as a whole, not address forms or location-based filling).
Undeliverable as Addressed Mail (Report No. MS-AR-14-006)
In FY2013 the US Postal Service processed over 158 billion pieces of mail, and nearly 6.8 billion (4.3 percent) could not be delivered as addressed (UAA), at an estimated handling cost of $1.5 billion; causes include moves and illegible addresses. It shows that wrong addresses are a measurable, systemic cost.
Management Advisory – Strategies for Reducing Undeliverable as Addressed Mail (Report No. MS-MA-15-006)
In FY2014 there were 6.6 billion pieces (4.3 percent) of UAA, USPS spent nearly $1.5 billion on handling and the industry about $20 billion a year; about 40 percent of UAA came from the public, 35 percent from mailing businesses (such as address lists not updated), and about 23 percent from the Postal Service itself. It supports checking addresses at the source, when members fill them in.
Construction, Maintenance and Application of Address Geocoding (in Chinese)
Report of the Department of Statistics, Ministry of the Interior: when five datasets were matched against the address master file (ADR), Taipower at 88.91% was lower, all the others were at 96% or higher, and household registration data at 99.59% was highest; it also notes that "the nationwide house-number location dataset contains some wrongly split addresses", and that from 2022 the household and residence registration village/neighborhood house-number data became the master file. It shows that even official house-number data have format gaps, so after location-based filling the address is still passed to the existing house-number matching for checking.
Regulation (EU) 2016/679 (General Data Protection Regulation), Article 5
GDPR Article 5(1)(c) data minimisation: personal data must be "adequate, relevant and limited to what is necessary"; and (e) storage limitation: data must not be kept longer than the purpose requires. HowBridge uses coordinates only for the current house-number query and does not write them to member data, which is in line with this international principle; the GDPR is an EU regulation and is used here only as an international reference, not as a law that applies in Taiwan.
The flow follows the HowBridge server code as of 2026-10-06; the test results are direct calls at 12 coordinates on that day and do not represent every place. The "300,000 per month" in the TGOS application notes is the matching-query quota for advanced use, and whether coordinate-to-address lookups are counted separately is not stated officially, so this page does not infer it. For the Personal Data Protection Commission Preparatory Office interpretation, only the reproduction in the Taipei City Laws and Regulations Database was read, and the original was not obtained. The test coordinates are points near public landmarks, not any member's location.
What are the common questions about filling in an address from your current location?
Does HowBridge connect to the Ministry of the Interior's coordinate-to-address service?
Does this mean the Ministry of the Interior certifies or endorses HowBridge?
After I press the button, is the address saved automatically?
Will HowBridge keep tracking my location?
Why does the filled-in address have no floor?
Why is the house number found not my home?
Why does it show "No house number found nearby"?
Can I use it in the app or on LINE?
I blocked location. How do I turn it back on?
How often is TGOS house-number data updated?
Can I use it when I am abroad?
Further reading
TGOS house-number matching: HowBridge gets approval to use Ministry of the Interior TGOS
Chunghwa Post NSDA: postal check of delivery addresses
Disaster notices: judging the affected area from your delivery address
HowBridge LINE official account guide
How to read consolidation shipment status
Privacy Policy
At the delivery location? One press fills in the address
Go to the Member Center, add a Taiwan home-delivery recipient, press "Use current location to fill in address", confirm the house number, add the floor, and save.
Try it in the Member Center