Countries
Mexico Postal Codes and Addresses Guide
How Mexico's five-digit código postal system works, why the colonia matters in a Mexican address, and how a UPCS exact-location code fits in.
Updated 14 October 2026 · 3 min read
Mexico uses a five-digit postal code, called the código postal, which is usually written as five numbers with no separator. The national postal service is Servicio Postal Mexicano, commonly known as Sepomex. In a Mexican address, the neighbourhood, called the colonia, is as important as the street, and the postal code is closely linked to it.
How the national system works
Each código postal covers a defined delivery area, normally a colonia or a group of them. A large colonia may have one code, and in a big city several neighbouring colonias may share a code. The first digits of the code relate broadly to the state or the Mexico City area, so the code also helps with regional sorting. See Mexico postal code format for more detail.
Many people and businesses also use private courier companies for parcels, so a postal code often serves as a routing and address-validation field in online forms as much as a postal one.
How addresses are written
Mexican addresses typically put the street name first and the number after it, then the colonia, then the code with the municipality or city, and the state. A common layout:
Jane Doe
Calle Ejemplo 123, Int. 4
Col. Ejemplo
12345 Ciudad Ejemplo, Estado
MEXICO
Numbers are often called exterior (outside) and interior (apartment or unit). Where there is no number the abbreviation S/N, for "sin número", appears. See the Mexican address format page for details.
How UPCS codes work in Mexico
UPCS (Universal Post Code System) generates a short code for an exact point on the map. In Mexico it starts with MX, then two blocks of letters and digits, for example MX-XXXX-XXXX (a placeholder). Each code stands for a 3 m by 3 m grid cell, and the same coordinates always give the same code.
A UPCS code is not an official postal code, is not issued by Sepomex or the government, and does not replace the código postal or the colonia. It is a complement that shows exactly where a delivery should go, which is helpful where streets lack numbers or reference points are used.
In this guide
Four more pages cover the topic. Postal code format explains the five digits. Address format shows the order of the lines. Find a postal code helps with lookup and checking. Delivery and addressing covers real-world challenges for couriers and shops. You can also open the countries hub.
In this guide
Frequently asked questions
What is a código postal?
It is the Spanish term for postal code. In Mexico it has five digits and is tied to a neighbourhood (colonia) or area rather than to a single street.
What do Mexican UPCS codes look like?
They begin with the prefix MX, followed by two blocks of letters and digits, as in MX-XXXX-XXXX. UPCS codes are not official postal codes.