ZipCode Checker User Guide – Easily Verify Any Postal Code

What Is a Postal Code?

A postal code (or zip code) is a numeric or alphanumeric code assigned to geographic areas to facilitate mail delivery. Different countries have their own rules: China uses 6‑digit numbers, the US uses 5‑digit numbers (with an optional +4 extension), and the UK uses mixed alphanumeric codes like SW1A 1AA. Accurate postal codes are essential for logistics, e‑commerce, and address verification.

How to Use This ZipCode Checker Tool

Just three steps to quickly determine if your postal code matches the expected format for its country:

1. Paste or type the postal code into the input field (spaces are automatically trimmed).
2. Click the “Validate” button.
3. View the result – the tool tells you whether the format is valid.

You can click on any example code to test it instantly. This ZipCode Checker supports most common global formats, and the backend validates against defined rules.

This tool is completely free, no registration required – ideal for e‑commerce sellers, logistics professionals, and everyday users.

Frequently Asked Questions

1. Does the postal code validator guarantee that the address actually exists?

This ZipCode Checker verifies the format only – it does not confirm whether the postal code corresponds to a real address. For address authenticity, please consult a mapping service or the official postal system.

2. Why does my postal code show as invalid?

Possible reasons: incorrect length (China requires exactly 6 digits); disallowed characters (China and the US allow only digits; the UK allows letters and numbers); or the format doesn't match the country's rules. Double‑check and try again.

3. Which countries does this tool support?

It supports most countries and territories worldwide, including China, the US, the UK, Canada, Germany, France, Japan, and many more. The backend automatically applies the appropriate rule based on the country you select.

4. Does it support US ZIP+4 (e.g., 90210-1234)?

Yes. You can enter either the 5‑digit or 9‑digit format (with a hyphen). The ZipCode Checker cleans the hyphen and validates the digits.

5. Do I have to pay for this?

Not at all – it’s completely free. OkeyTool is dedicated to providing useful online utilities for everyone.

If you have any other questions or encounter any issues, feel free to reach out via the contact links at the bottom of the site. Thank you for using ZipCode Checker!