About CalcularRFC | CalcularRFC.mx

CalcularRFC.mx is an independent project maintained by Martin Kreitl, offering an accessible RFC calculator and an explanation of its results.

Editorial responsibility and checks

Martin Kreitl maintains the project and its implementation. Technical tests check reference cases and software rules; they are not an independent tax review. We do not attribute Mexican tax credentials to the maintainer or name a professional reviewer without a verifiable review. Changes to rules, tables or examples must be checked against applicable sources; a technical check date does not establish that an official procedure is current.

What we provide

We provide an estimated calculation and guides linking to the relevant institutions’ services. The tool is free, does not require an account and does not send your form details to a server.

Sources and corrections

The calculation uses the rules published by SAT in response to IFAI request 0610100135506. We distinguish mathematical checks from the official assignment of a key. If you find an error, report it through our contact page without including personal information.

Our independence

We are not SAT, IMSS, RENAPO or UNAM. We do not provide personalised tax advice or certify that a key exists in the registry.