Mexico – Tax ID Number (RFC)

The Tax ID Number (RFC) is issued by the Tax Administration Service (Servicio de Administración Tributaria). Tax ID numbers can be issued to both people and companies.

Tax ID Numbers for Individuals

When an RFC belongs to a person, it has 13 characters. It is structured as follows:

• Four letters from the person’s legal name following similar rules to the CURP’s first four letters
  • First letter and first internal vowel of the paternal surname
    • If the paternal surname does not have a first internal vowel, the second letter of the paternal surname is used.
    • If the person does not have a second surname, first two letters of the paternal surname are used.
  • First letter of the maternal surname
    • If the person does not have a second surname, the first letter of the given name is used.
  • First letter of the given name
    • If the person does not have a second surname, the second letter of the given name is used.
• The individual’s six-digit birth date in YYMMDD format
• A three-digit checksum assigned by the Tax Administration Service

To better understand the RFC, consider an individual with the following details:

• Name: Juan Carlos Hernandez Garcia
• Date of birth: May 6, 1982
• Final three check characters assigned by the Tax Administration Service: M10

Given Garcia’s personally identifiable information (PII), his RFC will be:

HEGJ820506M10

As covered in the Sayari Learn article on Mexican naming conventions and their impact on ID numbers, the names José and María are typically ignored when constructing ID numbers.

Consider an individual with the same PII as Juan Carlos Hernandez Garcia but with the name José Alonso Hernandez Garcia. In this instance, José is ignored when constructing the RFC and Alonso is used as the given name instead. The resulting RFC will be:

HEGA820506M10

In public records, people sometimes provide only the first 10 characters of their RFC without the check characters. This partial RFC can be used when an individual wants to provide an ID number but maintain their privacy.

There are several additional rules to know:

• If the person does not have a maternal surname, the first four letters of the RFC follow a different format. The first two letters are the first two letters of the paternal surname regardless if the second letter is a vowel or consonant. The third and fourth letters are the first two letters of the given name regardless if the second letter is a vowel or consonant.
• If a woman is married, her maiden name is used.
• If the name includes apostrophes, they are ignored.
• If the first four letters of the RFC form an inappropriate word, the fourth letter will be replaced with an X.

Tax ID Numbers for Legal Entities

An RFC for a legal entity features 12 characters. It is structured as follows:

• Three letters from the company’s legal name that depend on the length of the company name (excluding the corporation type at the end of the name and the stop words de, del, los, las, el, la, en, y, and e):
• If the company name is three words or greater, the three-letter string will comprise the first letter of each word. For example, if the company’s name is El Gato Azul Restaurante, S.A. de C.V., the RFC would start with GAR.
• If the company name is two words, the three-letter string will comprise the first letter of the first word and the first two letters of the second word. For example, if the company’s name is Gato Azul, S.A. DE C.V., the RFC would start with GAZ.
• If the company name is one word, the three-letter string will comprise the first three letters of the word. For example, if the company’s name is Gato, S.A. de C.V., the RFC would start with GAT.
• The company’s six-digit incorporation date in YYMMDD format (sometimes this date will differ by a few days from the company’s official date of incorporation)
• A three-character check value assigned by the Tax Administration Service.

There are several additional rules to know:

• If there is a number in the company’s name, it will be spelled out and follow the same rules as a standard RFC. For example, if the company’s name is 4 Gatos, S.A. de C.V., since number four is cuatro in Spanish, the company’s name will be written as Cuatro Gatos, S.A. de C.V. Therefore, the RFC would start with CGA.
• Sometimes, the RFC will include the words y and e rather than ignoring them in the construction of RFCs. Similarly, the phrase y compañía (and company in English) will sometimes be ignored entirely, but other times the C from the word compañía will be used.