The Federal Revenue began issuing CNPJs containing letters and numbers in July 2026. This modification was introduced with the purpose of increasing the range of available combinations for new registrations, given the increase in demand and the possibility of exhausting options in the purely numeric format.
The first CNPJ with an alphanumeric format was registered on July 31, intended for a branch of Banco do Brasil. It is important to note that companies that already have a CNPJ do not need to make any changes; their current records remain valid without modifications.
The new standard will only apply to new registrations and will be implemented gradually. Although the identifier maintains its 14 positions, it will now allow the combination of digits from 0 to 9 and any of the 26 letters of the alphabet, always in uppercase. The structure will be represented as AA.AAA.AAA/AAAA-DV, where the alphanumeric positions can contain letters or numbers, and the last two characters function as a verification digit.
This change was previously planned by the Federal Revenue. Normative Instruction RFB No. 2,229, released in October 2024, formalized the alphanumeric format and stipulated its entry into force starting in July 2026.
According to the Revenue, the main goal is to raise the number of possible combinations and ensure the continuity of records in the registry. The assignment of these letters and numbers is managed by the Federal Revenue system, and the transition will occur progressively, meaning that new registrations with purely numeric identifiers may still appear during the implementation period.
Although it does not require immediate action from already registered companies, it is essential that these businesses' systems are ready to process identifiers containing letters. The Federal Revenue issued a warning stating that applications using its services that have not been adapted may present failures. This covers systems integrated via Webservices or APIs, as well as other tools that manipulate CNPJ data, requiring verification of management and registration systems.
The adaptation guidance is not limited to companies. Agencies and entities that directly access the Revenue's database have also been instructed to adjust their systems to the new format. Serpro, responsible for processing Revenue data, has also made the necessary adjustments to enable this change.
The implementation followed a staggered schedule. According to the official plan, systems began operating on July 27, 2026, with the first alphanumeric CNPJ being put into use on July 31.