Why a form will not accept your postcode

A form rejecting your postal code usually means one of six things. In order of how often they actually turn out to be the cause:

1. A spreadsheet ate the leading zero

By far the most common. Open a list of codes in a spreadsheet and 01067 silently becomes 1067 — a number, not a code. Dresden's real code is five digits; four digits is not a valid German code at all, so every form will refuse it.

Format the column as text before pasting, not as a number. If a list has already been mangled, the fix is to pad it back to the country's length — our code checker flags exactly this, and tells you what the code should have been.

2. It is the right code for the wrong country

Codes look interchangeable and are not. 1000 is valid in Belgium, Bulgaria and the Philippines, and invalid in Germany. Check the country is set correctly before assuming the code is wrong.

3. The country does not use postal codes

61 countries and territories have none, and many checkouts still demand one anyway. See the full list and what to type instead.

4. Spacing or case

Some countries write the code with a space in it and some forms only accept one form or the other. UK codes are conventionally written with a space before the last three characters, Dutch codes with a space before the two letters. If one form is refused, try the other. Codes containing letters should generally be entered in capitals.

5. The code is real but too new

Postal operators add codes for new developments, and address databases lag — sometimes by years. If the code is on your official post and a site still rejects it, the site's data is stale, not your address.

6. It is a P.O. Box or a large-recipient code

Some countries issue separate codes for P.O. Boxes, and dedicated codes to organisations receiving large volumes of mail. These are valid but often missing from third-party validation lists.

Checking a code properly

Our bulk checker tests a whole list against the real format for a country and names the place each code belongs to, without uploading anything. For a single address the destination country's own postal service is the authority, and every country page here links to its official finder.