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Alphanumeric CNPJ

Everything about the new alphanumeric CNPJ format: IN RFB 2.119/2022, what changes for businesses, new structure with letters and numbers, and how to prepare your systems.

8 min read Updated on July 2026

In this guide, you will:

  • Understand what the alphanumeric CNPJ is and why it exists
  • See the new format and where the letters go
  • Learn what changes for businesses and systems before July 2026
  • Validate and generate CNPJs in the new format

What is the alphanumeric CNPJ?

Starting July 2026, the Brazilian Federal Revenue Service will begin issuing alphanumeric CNPJs. The change, established by IN RFB 2.119/2022, was necessary because numeric-only CNPJs were running out due to the growing number of registered companies in Brazil.

Why the change?

With over 50 million businesses registered, the numeric CNPJ format (14 digits, numbers only) was approaching exhaustion. The alphanumeric format dramatically increases the number of possible combinations by including letters A-Z in positions that were previously numbers-only.

The new format

The new CNPJ maintains 14 characters but allows letters (A-Z) in the first 12 positions. The last 2 digits remain as numeric check digits calculated with a modified Modulo 11 algorithm that assigns numeric values to letters (A=17, B=18... Z=42).

Current format
12.345.678/0001-95
Numbers only
New format
AB.C45.678/0001-72
Letters + numbers

Impact on businesses and systems

Existing numeric CNPJs remain valid. Only new registrations from July 2026 onward may receive alphanumeric identifiers. Systems that validate or process CNPJs must be updated to accept letters in the first 12 positions.

Important

Systems that validate, store, or process CNPJs must be updated before July 2026 to accept letters in the first 12 positions. The length (14 characters) and the check-digit calculation stay the same.

Want to try it? Use the Alphanumeric CNPJ Validator to check a number in the new format, or the Alphanumeric CNPJ Generator to generate valid examples.

Timeline

IN RFB 2.119/2022 was published in December 2022. The implementation date was set for July 2026, giving businesses and developers over 3 years to prepare their systems for the new format.

The alphanumeric CNPJ changes neither the length nor the check-digit calculation — it changes the set of characters allowed in the first 12 positions, which now include letters. Anyone validating CNPJs on their own needs to update the rules before July 2026. Try the new format with the tools below.

Frequently Asked Questions

What is an alphanumeric CNPJ?
An alphanumeric CNPJ is the new format for Brazilian business registration numbers that allows both letters (A-Z) and numbers (0-9) in its composition, instead of only numbers as in the current format.
When does the alphanumeric CNPJ start?
The alphanumeric CNPJ format begins in July 2026, as established by IN RFB 2.119/2022 from the Brazilian Federal Revenue Service.
Will my current CNPJ change?
No. Existing numeric CNPJs remain valid and unchanged. The alphanumeric format only applies to new registrations issued from July 2026 onward.
How are check digits calculated in the alphanumeric CNPJ?
The check digits use a modified Modulo 11 algorithm where letters are assigned numeric values (A=17, B=18, ..., Z=42). These values are multiplied by the standard CNPJ weights and the check digits are calculated as usual.
Why is the CNPJ changing to alphanumeric?
The numeric-only format was approaching exhaustion with over 50 million registered businesses. Adding letters exponentially increases the number of possible combinations, ensuring the identifier system can serve Brazil for decades.