- The RFC is Mexico's tax identification number, issued by the SAT.
- You need a CURP first, which comes from your immigration document.
- Registration is one appointment and the RFC is issued the same day.
- The hard part is getting the appointment, not the paperwork.
- Next come the e.firma digital signature and your tax status certificate.
What the RFC actually is
The Registro Federal de Contribuyentes is the Mexican taxpayer registry. Your RFC is the code it assigns you, built from your name and date of birth plus a verification suffix. Every invoice issued in Mexico carries the RFC of both parties. Every filing, every contract with a serious company and every bank onboarding form asks for it.
It is not the same as a CURP. The CURP is a population registry number that identifies you as a person living in Mexico, citizen or resident. The RFC identifies you as a taxpayer. You normally need the first to get the second.
Who needs one
- Anyone with Mexican-source income. A Mexican client, rental income from a Mexican property, a Mexican salary. No exceptions.
- Anyone who becomes a Mexican tax resident, under the rules we cover in the tax residency guide.
- Anyone buying property. The notary will require it to close.
- Practically: anyone settling here. Banks, insurers, utilities, gyms and landlords ask for it routinely, and the answer "I'm a foreigner" stopped working years ago.
Getting an RFC does not by itself create Mexican tax liability, and it does not make you a tax resident. It registers you in the system. What creates liability is income and residency, which are separate questions.
What you need to bring
- Your resident card, temporary or permanent, or the immigration document that applies to you.
- CURP, which is generated from your immigration record.
- Proof of address in Mexico, no more than three months old — a utility bill or bank statement in your name, or a lease with supporting documents.
- A valid email address and phone number, which become part of your tax record and are used for the electronic mailbox.
- Passport.
Get the address right the first time. An outdated registered address is one of the most common causes of trouble later: official notices are served electronically and to your registered address, and "I never got it" is not a defence in Mexico.
The SAT booking portal showing no availability is the number one reason foreigners stall on this. We get the appointment, prepare the file and go with you.
Get help with my RFCWhat comes immediately after
The e.firma
Your digital signature certificate. It is what lets you file returns, sign electronically and complete most SAT procedures online. It requires an in-person appointment with biometric capture, and it expires — a lapsed e.firma at the wrong moment is a genuinely disruptive problem.
The Constancia de Situación Fiscal
Your tax status certificate, showing your RFC, address and regime. Clients and employers request it constantly and they want a current one. It is free and downloadable in seconds once you are registered.
Choosing your tax regime
This is the decision with real money attached and the one people make carelessly. If you are an individual with professional income under the annual ceiling, the simplified RESICO regime taxes gross collected income at 1% to 2.5% with no deductions. The general regime lets you deduct expenses but applies progressive rates up to 35% on profit. Which is better depends entirely on your expense ratio, and switching later is not always free.
The Buzón Tributario, and why it matters from day one
When you register, you activate an electronic mailbox called the Buzón Tributario. The SAT serves everything through it: information requests, assessments, audit notices. Legal deadlines start running when a document is deposited there, whether or not you ever open it.
Foreigners are especially exposed here, because the notices arrive in Spanish, in dense legal language, and often about something that seems minor until it is not. Somebody should be watching it. That is exactly what our tax defense plans do, and if a deadline has already been missed, the route back is usually a tax amparo or an administrative appeal.