What is my postal code?
Postal codes are not one format but dozens, and how much they give away differs wildly. A Dutch code narrows you to one side of one street; an Irish Eircode identifies a single building; a large rural code can cover a whole district. That is worth knowing before you paste yours into a form.
Your browser will ask before sharing anything. Nothing is uploaded.
Your postal code can be shown above once you allow location access. Postal code is the international term for what the United States calls a zip code: a short alphanumeric code that groups nearby addresses. Formats vary widely, from the four-digit codes in much of Europe to the letter-and-number codes of the United Kingdom, Canada and the Netherlands.
We derive it the same careful way as everything in the Location group: your browser fixes your position only after you press the button and accept the prompt, and this page then sends those coordinates to a public reverse-geocoding service, OpenStreetMap Nominatim, to look up the postal code. We never see or store your coordinates ourselves.
Because formats differ by country, the exact look of your postal code depends on where you are. What stays constant is the method: consented, transparent about the one lookup involved, and easy to skip if you would rather not share.
How a website reads this
This is the exact call a page makes. Nothing else is involved, and nothing is sent anywhere: the value is read in your browser and displayed to you.
navigator.geolocation.getCurrentPosition then a reverse geocodeThe same two steps as the ZIP page, aimed at the rest of the world. What comes back varies by country: six characters in the Netherlands, a mixed alphanumeric outercode and incode in the United Kingdom, four digits in much of continental Europe, and nothing at all in the handful of countries with no postal code system.
- Needs your permission
- Yes, your browser asks first
- Can it be faked
- Yes. Follows the coordinates, as the ZIP lookup does.
- Contribution to a fingerprint
- Not counted. Not part of the fingerprint estimate: consent-gated. How we estimate this.
How much a postal code gives away, by country
Postal codes are not one system but dozens, and how precisely they locate you differs enormously. Worth knowing before typing yours into a form.
| Country | Format | How precise |
|---|---|---|
| Netherlands | Four digits plus two letters, such as 1011 AB | One side of one street, often a handful of buildings. Combined with a house number it is a complete address |
| United Kingdom | Outward and inward code, such as SW1A 1AA | Typically around 15 addresses, sometimes a single large building |
| Ireland | Eircode, seven characters | A single property. Uniquely among these, it identifies one building by design |
| Germany | Five digits | A district within a city, or a whole small town |
| France | Five digits | A commune, which can be a Paris arrondissement or an entire rural village |
| United States | Five digits, optionally plus four | A delivery route. Very broad in rural areas, narrow in cities |
| Canada | Six characters, such as K1A 0B1 | In cities, roughly one city block or one side of a street |
Two countries stand out for the wrong reason. A Dutch code plus a house number, or an Irish Eircode on its own, is effectively a street address. Handing either to a form is not the same act as handing over a five digit US ZIP.
Countries with no postal code at all
Ireland had none until 2015. A number of countries, including Hong Kong, the United Arab Emirates and several African and Caribbean states, still operate without a national postal code system. If you are in one of those, this lookup returns nothing, and that is the correct answer.
It is also a recurring bug in web forms: a required postal code field with a rigid five digit pattern silently excludes a large part of the world. If you build forms, this table is the argument for making the field optional and the validation loose.
What you should know
Why sites collect it
Forms request a postal code for shipping quotes, tax and duty calculation, service-area checks, and local search. It is the smallest locator most e-commerce needs, which is why it is asked for so often.
Privacy implications
A postal code pins you to a small area. In sparsely populated regions it can be quite precise, so treat it as moderately sensitive. Deriving it here from consented coordinates, shared only with a public geocoding service and never with us, keeps you in control of whether it is read.
How to change or hide it
Skip the location prompt to avoid it, or revoke access afterwards. When entering it elsewhere, share your postal code only where delivery, tax or availability genuinely require it.
Frequently asked questions
Is a postal code the same as a zip code?
Effectively yes. Zip code is the United States term; postal code is the international one. Both group nearby addresses, though formats differ by country.
Why does my postal code look different from a US zip?
Postal code formats vary by country. Many use different lengths or mix letters and numbers, so yours reflects your country's scheme.
Sources
Browser behaviour changes and vendors cap these values differently, so the claims above that are not self-evident are checked against the specifications and vendor documentation below.
Last checked on . How these values are measured and estimated is set out on the methodology page.
Something wrong here? Tell us what your browser reports and it gets corrected.