What Is a CEP? How a Brazilian Address Is Built

The digits are a funnel, not a label

Read a CEP left to right and you are zooming in. The first digit is one of ten postal regions the country was cut into; each digit after it narrows the area, down to a sub-sector — which can be one stretch of one street, or one side of it.

The regions were not drawn by geography alone. The Correios describe them as set by socioeconomic development and population growth, with the numbering handed out anticlockwise starting from São Paulo — which is why region 0 is greater São Paulo and region 9 is Rio Grande do Sul, at the far south. That is the Correios' own description, in their own text, not folklore.

The eighth digit is a real check digit, with a published formula — not decoration. Which is how a typo in a CEP can fail validation instead of quietly routing a parcel to the wrong state.

Some places have one CEP for the whole locality. That is not a gap in the system: it is what happens where addresses were never coded street by street, and it persists in smaller towns. A single CEP can also belong to one recipient — a bank, a government body, a building that receives enough mail to earn its own code.

Why the number comes after the street

To a Brazilian system, the street is one closed unit: a type plus the official name assigned by the municipality. Rua, Avenida, Travessa, Alameda — the type is part of the name, not a description of it.

The number is a separate field, and its stated job is to identify the building on that street. So the order is not stylistic preference reversed from English: it is nominate the street, then point at a spot on it. Which is also why a Brazilian form will reject the whole address if you paste "123 Rua Augusta" into the street box — the number does not belong there.

Two consequences bite foreigners. Addresses without a number use S/N — sem número — and that is a real value, not a blank. And the list of street types you find published is a list of examples, not a closed set: other types exist, and the international reference sheet for Brazil lists several the domestic page does not.

The CEP outranks what you wrote

This is the part that changes behaviour, and it is stated plainly in the Correios' own technical guide: sorting is mechanised, and the code is what the machine reads.

If the CEP and the written address disagree, the item follows the CEP. Nothing catches the contradiction at the moment it matters, because nothing human is reading. The error surfaces at the far end, where a person finally looks at the label and finds the item in the wrong city.

The practical rule for anyone sending something to Brazil: verify the CEP against the street, not the other way round. A correct street with a wrong CEP is worse than an incomplete address, because it fails silently and confidently.

The complemento is where deliveries die

Complemento covers apartment, block, floor, unit, shop — anything identifying a dwelling inside a building. Real examples the Correios publish are as plain as Loja B.

It is not an afterthought field. The official label spec reserves 30 characters for it, against 6 for the number and 8 for the CEP. And "missing complemento" is a named, numbered reason for returning an item, printed on the back of the standard envelope, resting on the postal law's provision about addressing that does not allow correct delivery.

So an address that reaches the right building and cannot name the flat is not almost-right. It is a documented return.

Brasília works differently enough to break every rule above: no street names at all, but a sector abbreviation, then quadra, then block. In the Federal District the administrative region takes the place you would expect the neighbourhood to occupy.

Sending from abroad: whose format wins

The rule most people get backwards is simple, and the UPU states it as a recommendation rather than a requirement: the country line follows the conventions of the country you post from; everything above it follows the destination.

An American posting to Brazil does not translate the address into US shape. They write the Brazilian address as a Brazilian would — street type and name, number, complemento, neighbourhood, city, state abbreviation, CEP — and then write BRAZIL on the last line, in their own language, for their own postal service to read.

The same instinct that makes people rewrite an address makes them rewrite a phone number, and Brazilian numbers have their own trap. If a form is asking for your address, it will probably ask for a CPF too, and why the cashier wants that number has its own answer — above a threshold, the receipt wants an address as well. Getting a CPF as a foreigner is a separate errand, as is having a document apostilled. Buying a SIM card will ask you to register somewhere; paying by PIX will not ask for an address at all; and if none of this applies yet, start with whether you need a visa.

Sources

• Correios, Tudo sobre CEP — the structure of the code and the suffix ranges. Accessed September 3, 2026.
• Correios, Guia de Endereçamento — field definitions, label character limits, and the reasons an item is returned. Accessed September 3, 2026.
• Correios, CEPNet technical guide — mechanised sorting and the check-digit formula. Accessed September 3, 2026.
• Correios, archived structure page (2006) — the ten regions and the anticlockwise numbering, in plain text. Accessed September 3, 2026.
• Law 6,538/1978 — the postal law, including the definition of the code and the addressing provision behind returns. Still in force; the Supreme Court upheld it in 2009. Accessed September 3, 2026.
• UPU, Addressing systems: formatting an international address — the country-line recommendation, January 2010. Accessed September 3, 2026.

What we could not verify

• The CEP ranges by state. The Correios publish a lookup that answers this for a human, but it sits behind a CAPTCHA, including on the range search. We did not work around it, and there is no open dataset: the Correios publish that, as a state company, they are outside the open-data decree, and the full address base is a paid product.
• The exact month the code was introduced and later extended. An archived Correios page says May 1971 and May 1992; the timeline the Correios publish today says 1970 and has no entry for the change to eight digits at all. Two official sources, two answers, so we give the decade rather than pick one.
• Which regulation the postal law delegates the code's structure to. The law refers to a regulation, and a 2025 decree governs postal services in general — but neither fixes the eight digits. The ordinance the CEP page itself links to is about universal service and delivery deadlines, not the structure of the code.