RFC and e.firma

These are what my clients get stuck on more than anything else, including the licences themselves.

Neither is complicated. Both are one-shot appointments where a single missing document sends you away, and the cost of that is measured in weeks rather than hours.

What an RFC is

El RFC es una clave alfanumérica que identifica a cada contribuyente ante la autoridad fiscal.

The Registro Federal de Contribuyentes is your tax identification number, issued by SAT, the Servicio de Administración Tributaria. It identifies you to the tax authority and it is built from your own details rather than issued in sequence.

Persona física: 13 alphanumeric characters, derived from your name, your date of birth, and a government-assigned homoclave.
Persona moral: 12 alphanumeric characters, derived from the company name, the incorporation date, and a unique code.
If you form a company, that is two RFCs, not one. The company gets its own RFC and its own e.firma, separate from yours as an individual. You will still need your own.

What you cannot do without one

Open a Mexican bank account, or apply for a loan
Be formally employed, work as an independent contractor, or set up a company
Buy property or a vehicle, or set up utility accounts
Issue or request facturas, valid tax receipts

That last one is the one people underestimate. A business that cannot issue facturas cannot properly sell to other businesses.

What you need to get one

Three things, as a foreigner:

A resident permit. Either type is accepted. Temporary residency is enough.
Your CURP. This is usually issued when you get your resident permit, so most people already have one without having thought about it. Check that you can put your hands on it before the day.
A comprobante de domicilio, your proof of address.

The comprobante is where most people come unstuck, because the list of documents that pass without generating further questions is short:

CFE, your electricity bill
SEAPAL, your water bill
An internet, landline or contract mobile bill from Telmex, AT&T, Telcel, Totalplay or Izzi

It does not have to be in your name. It does have to be the address where you are actually staying, because that address becomes the one registered to your RFC.

Worth pausing on that second point. Whatever address is on the bill you hand over is the fiscal address attached to you from then on. If you use the bill for a place you are leaving in three months, your RFC is registered somewhere you no longer live, and correspondence from SAT goes there.

The e.firma, and the thing to bring

Your e.firma is your digital signature. Almost nothing can be filed without it, and you cannot process anything with COFEPRIS without one.

Two things about it that catch people out:

You have to ask for it. It is issued on the same day as your RFC, but it is not automatic. If you do not request it, you will leave with an RFC and no e.firma and have to go back.

Take your own USB drive. The e.firma is issued onto a USB and you are expected to bring one. Without it you do not leave with your e.firma.

It does not expire, which sounds like good news and mostly is. The consequence is that the USB matters more than people treat it. If you lose it you have to go back and obtain a new one, and part of that process is signing disclaimers releasing SAT from responsibility for anything done with it while it was out of your possession.

Treat it as a key rather than a file. Keep it somewhere you would keep a passport.

Why the appointment is the hard part

Everything above is knowable. What makes this difficult is the appointment itself.

Appointments are booked online. That has been the system since covid.

How far out they run depends entirely on the system on the day. Sometimes the next slot is tomorrow. Sometimes it is two weeks away. There is no pattern to it and no way to know before you look, which is why a licensing timeline that depends on an RFC cannot be promised in advance.

If you turn up early enough without an appointment you are occasionally seen. That is luck rather than a plan, and I would not build a timeline on it.

The office operates in Spanish. Not partly. If you cannot follow a fast conversation about document requirements, you are in trouble in the room.

Most people have not read the requirements properly when they booked. The requirements are stated, and they are stated in a way that assumes you already know how this works.

Many people do not have a proof of address, and only discover it matters when they are standing at the counter.

And one missing document means you are sent away to rebook. Not corrected on the spot, not resolved with a phone call. A new appointment, which can be anything from the next day to several weeks out.

That is the whole problem. It is not a difficult process. It is a process with no tolerance for being one document short, in a language most of my clients do not argue well in.

Getting everything right the first time is not a nicety here. It is the difference between a week and a month.

What I can and cannot do

I cannot do this for you. The appointment is yours and only you are allowed into the room. Anyone who tells you they can obtain your RFC on your behalf is describing something else.

What I do instead:

Help you through the appointment system
Confirm you have every document required before the day, in the form they want it
Come with you on the day, or send a member of my team who speaks Spanish

We wait outside, because only clients are allowed in. But you can call us from inside, and we will explain or translate while you are at the counter.

That is usually what makes the difference. Not the paperwork. Somebody on the phone who can answer the question being asked of you.

Business structures in Mexico, and where the RFC fits

Owning a company and being allowed to work in it are not the same thing

Which of this applies to you

Whether you need any of it, and in what order, depends on what the business will do and who owns it. I would rather ask than guess.

Book a discovery call