Definitions
A postal code is any system of numbers, letters, or both used by postal services to identify delivery areas and speed up mail sorting. Every country that has a formal postal system uses some form of postal code.
A ZIP code is the United States' specific implementation of a postal code. "ZIP" stands for Zone Improvement Plan, introduced by USPS in 1963. Learn more in our full guide: What Is a ZIP Code?
Key Differences
| Feature | ZIP Code (US) | Postal Code (Generic) |
|---|---|---|
| Format | 5 digits (or 9 with ZIP+4) | Varies: letters, numbers, or both |
| Country | United States only | Used worldwide |
| Authority | USPS | Each country's postal service |
| Example | 90210 | SW1A 1AA (UK), M5V 3C1 (Canada) |
| Extended version | ZIP+4 (e.g., 90210-1234) | Varies by country |
Postal Codes Around the World
- United Kingdom: Alphanumeric codes like "SW1A 2AA" - outward code + inward code. Very granular - can identify a single side of a street.
- Canada: 6-character alternating letter-digit format: "A1B 2C3". Called "postal codes."
- Australia: 4-digit numeric codes, very similar to US ZIP codes in concept.
- Germany: 5-digit numeric codes (Postleitzahl/PLZ).
- India: 6-digit numeric PIN codes (Postal Index Number).
- Japan: 7-digit codes with a hyphen after digit 3 (〒123-4567).
💡 Over 130 countries use some form of postal code. The US ZIP code is one of the most recognized systems, but each country's system is unique.
Filling Out Forms: What to Enter
When filling out international forms online:
- If the form says "ZIP Code" - it usually expects US-only input: 5 digits.
- If the form says "Postal Code" - it accepts codes from any country. Enter your country's format.
- Some forms auto-detect your country and adjust the field label accordingly.
Use our free ZIP code lookup tool to verify any US ZIP code. For non-US addresses, check your country's official postal service website.
FAQ
Q: Are ZIP codes used outside the US?
A: No. ZIP codes are exclusively a USPS system for US addresses. Other countries use their own postal code systems.
Q: Is "postcode" the same as "postal code"?
A: Yes - "postcode" is the British English term for postal code. Same concept, different word.
Q: Does Puerto Rico use ZIP codes?
A: Yes! Puerto Rico is a US territory and uses USPS ZIP codes starting with 00600–00988.