Postal Code vs ZIP Code — What is the Difference?

If you have ever filled in an international shipping form, you have probably seen the words postal code and ZIP code used side by side. They do the same job — helping postal services sort and route mail — but they are not exactly the same thing.

What Is a ZIP Code?

ZIP code is the United States Postal Service term, introduced in 1963. ZIP stands for Zone Improvement Plan. The basic format is five digits, such as 90210 (Beverly Hills, California). An optional four-digit extension — ZIP+4 — pinpoints an even smaller delivery segment.

What Is a Postal Code?

Postal code is the generic, international term used by most countries. The format varies widely from country to country:

Key Differences at a Glance

• Scope: ZIP code is specific to the US (and a few associated territories); postal code is the worldwide umbrella term.
• Format: ZIP codes are numeric (5 or 9 digits); postal codes can be alphanumeric and vary in length.
• Granularity: a UK postcode typically covers around 15 addresses, while a US ZIP code can cover thousands.

Why the Difference Matters

When mailing internationally, always use the destination country's local format and terminology. A parcel addressed with a US-style ZIP code to Germany will not sort correctly — Germany expects its 5-digit PLZ instead.