How many digits is a Mexican postal code?

A Mexican código postal (CP) is exactly 5 digits, written without spaces — for example 06000 for Mexico City Centro. Leading zeros are significant, so 06000 is not the same as 6000.

How does the state mapping work?

SEPOMEX assigns blocks of postal codes to each state. The first one or two digits indicate the state — for instance 0 covers Mexico City, 44–49 cover Jalisco, and 64–67 cover Nuevo León. This tool maps the prefix to the state.

Does a valid format mean the CP exists?

No. Passing the format and prefix check means the code is well-formed and falls in a real state block. It does not confirm the exact CP is assigned to a delivery zone — use the official SEPOMEX database for that.

Why does my CP show as out of range?

Mexican postal codes run from 01000 to 99998. A code outside that range, or with the wrong number of digits, is rejected as malformed.

Is my postal code sent anywhere?

No. The check runs entirely in your browser using a built-in prefix table. Nothing is uploaded.

Mexico Postal Code Validator

A Mexican código postal (CP) is the 5-digit code SEPOMEX (Servicio Postal Mexicano) assigns to every delivery zone. The numbering plan is geographic: each state owns one or more blocks of leading digits, so the first one or two digits of any valid CP tell you which state it belongs to. This free validator checks the format and resolves the state, which is handy for e-commerce checkout validation and cleaning Mexican address data.

How it works

Strip non-digits and confirm the result is exactly 5 digits.
Confirm the numeric value is within the assigned range (01000–99998).
Read the leading digits and match them against the SEPOMEX state blocks. Mexico City uses the 0xxxx range; states like Jalisco (44–49), Nuevo León (64–67) and Yucatán (97) own contiguous prefix bands.

The tool returns whether the code is well-formed and, when it is, the state the prefix maps to.

Example

For 06000, the format is valid (5 digits, in range) and the leading 0 resolves to Ciudad de México. For 44100, the prefix 44 resolves to Jalisco (Guadalajara). A 4-digit entry like 6000 is rejected because Mexican codes always carry their leading zero.

Notes

A passing result means the CP is structurally valid and lands in a real state block — not that the specific code is an assigned delivery zone. For authoritative per-CP data (colonia, municipio), query the official SEPOMEX dataset. All processing here is local to your browser.