Regex for us zip code

Match a US ZIP code in 5-digit or ZIP+4 (5-4) format.

The pattern

^\d{5}(-\d{4})?$

Try it in the explainer →

What it matches

12345
90210
12345-6789

What it doesn't match

1234
123456
ABCDE
12345-678

How it works

Token-by-token breakdown:

^: Anchor to the start.
\d{5}: Exactly 5 digits — the base ZIP code.
(-\d{4})?: Optional: a hyphen followed by exactly 4 more digits (ZIP+4 extension).
$: Anchor to the end.

Edge cases & gotchas

Doesn't verify the ZIP code corresponds to a real US location
Some ZIP codes start with 0 (e.g. 02134 in Massachusetts) — pattern handles this correctly
Doesn't accept ZIP codes with spaces instead of hyphens (12345 6789)
For Canadian postal codes (A1A 1A1) or UK postcodes, use entirely different patterns

Per-flavor variants

The pattern is identical across JavaScript, Python, and PCRE for this case. If you need to convert a flavor-specific pattern, use the flavor converter.

JavaScript	`^\d{5}(-\d{4})?$`
Python	`^\d{5}(-\d{4})?$`
PCRE	`^\d{5}(-\d{4})?$`

When NOT to use this regex

For address validation or normalization, use a postal-service API (USPS API, SmartyStreets, Lob). They verify the ZIP exists, attach a city/state, and confirm a deliverable address — which regex cannot do.