What is the RFC?
The RFC (Registro Federal de Contribuyentes) is the tax identification number that Mexico's tax authority (SAT) assigns to every individual or company that carries out economic activities or has tax obligations in Mexico.
The RFC is an alphanumeric code that uniquely identifies each taxpayer:
| Element | Individuals | Companies (Personas Morales) |
|---|---|---|
| Length | 13 characters | 12 characters |
| First characters | 4 letters (surnames + first name) | 3 letters (company name) |
| Birth/incorporation date | 6 digits (YYMMDD) | 6 digits (YYMMDD) |
| Homoclave | 3 alphanumeric characters assigned by SAT | 3 characters |
What is the RFC used for?
The RFC is the foundation of your tax identity in Mexico. Without it you cannot perform virtually any formal financial or tax operation:
| Procedure / Operation | RFC required? |
|---|---|
| Issue electronic invoices (CFDI) | ✅ Mandatory |
| Receive tax-deductible invoices | ✅ Mandatory |
| File tax returns at SAT | ✅ Mandatory |
| Register in RESICO or any tax regime | ✅ Mandatory |
| Open a business bank account | ✅ Mandatory |
| Incorporate a company (Persona Moral) | ✅ Mandatory |
| Hire employees and register with IMSS | ✅ Mandatory |
| Obtain the e.firma SAT | ✅ Prior requirement |
| Use the tax mailbox (buzón tributario) | ✅ Mandatory |
| Request a tax refund | ✅ Mandatory |
When are you required to register for RFC?
You must register if you:
- Carry out economic activities in Mexico (sell goods, provide services, rent property, etc.)
- Are an employee whose employer must register you with SAT
- Want to issue invoices (CFDI) for your services or sales
- Plan to incorporate a company in Mexico
- Receive income from abroad that must be declared to SAT
How to get your RFC for the first time
Option 1 — Online via SAT ID app
If you only need an RFC without activating a specific tax regime (e.g., to receive invoices or for bank account purposes), you can get it online:
- Download the SAT ID app (iOS / Android) or go to satid.sat.gob.mx
- Enter your CURP (Mexican population registry number)
- Complete facial recognition and upload a photo of your official ID
- SAT generates your RFC and sends it to your registered email
- Download your Constancia de Situación Fiscal as official proof
Option 2 — SAT portal (with tax regime activation)
If you are starting formal economic activity (invoicing, registering in RESICO, etc.) you need to register in a specific tax regime:
- Go to sat.gob.mx → "Otros trámites y servicios" → "Inscripción al RFC"
- Select the procedure for your situation: employee, business/professional activity, RESICO, rental income, etc.
- Enter your CURP and verify your identity
- Select the appropriate tax regime
- Download your Constancia de Situación Fiscal with your assigned RFC
Option 3 — In-person at a SAT office
If you cannot complete the process online (biometric failure, foreigner without CURP, or complex case), book an in-person appointment:
- Go to sat.gob.mx → "Citas" and book for "Inscripción al RFC"
- Bring the required documents for your profile (see table below)
- The SAT officer registers your information and hands you the Constancia de Situación Fiscal
Required documents for RFC registration
| Profile | Required documents |
|---|---|
| Mexican citizen with CURP | CURP, official ID (INE/passport), recent proof of address (max. 3 months old) |
| Foreign resident in Mexico | Valid passport, immigration document (temporary or permanent residence card), proof of address, CURP (apply at RENAPO first) |
| Foreigner without residency (occasional activity) | Valid passport, valid immigration document, proof of address in Mexico or home country |
| Company (Persona Moral) | Notarized incorporation deed (acta constitutiva), power of attorney for the legal representative, legal representative's RFC, company's tax address |
RFC for foreigners in Mexico
SAT can assign RFC to foreign nationals with or without tax residency in Mexico. The process varies by your immigration status:
- With temporary or permanent residence card: apply for RFC in person at SAT. You need a CURP, obtainable at RENAPO with your immigration document.
- With work visa (valid FMM): you can also apply in person, though additional documentation may be required.
- Foreign companies with activity in Mexico: must register as Personas Morales and designate a legal representative with RFC.
If you are planning to open a company in Mexico as a foreigner, the company's RFC is one of the first registrations after notarial incorporation. Our team can guide you through the entire process.
What is the Constancia de Situación Fiscal?
The Constancia de Situación Fiscal is the official SAT document that certifies your RFC, tax regime, tax address and fiscal obligations. The RFC is your number; the Constancia is the document containing it along with additional tax information.
Many companies, banks and government offices require the Constancia (not just the RFC number) to verify that you are correctly registered. You can download it at any time from the SAT portal using your password or e.firma.
RFC vs CURP: what is the difference?
| RFC | CURP | |
|---|---|---|
| Issued by | SAT (tax authority) | RENAPO (civil registry) |
| Purpose | Tax identification | Civil/citizen identification |
| Who has it | Taxpayers (individuals and companies) | All Mexicans and residents |
| Use | Invoices, tax filings, SAT procedures | Government, health, education procedures |
| Companies | Yes, they have their own RFC | Not applicable |
Frequently asked questions
Can I have two RFCs?
No. SAT assigns one RFC per individual or company. If you accidentally end up with two (which happens when someone registers twice), you must file a clarification notice to cancel the duplicate before SAT applies a penalty.
Does getting an RFC cost money?
No. RFC registration is completely free at SAT. Anyone charging you for the RFC itself is an unofficial intermediary. Professional accounting advice to choose the right tax regime and avoid errors from the start is a separate service — see our plans from $1,500 MXN/month.
Which tax regime should I register under?
It depends on your activity and income level. The most common options:
- RESICO: for individuals with annual income up to $3.5 million pesos — simplified obligations and lower rates. See our complete RESICO guide.
- Business and Professional Activity: for freelancers and small businesses with variable income.
- Rental Income Regime: if you rent out property.
- Salaries and Wages: if you are a formal employee (your employer registers you).
Choosing the wrong regime from the start can cost you significantly in unnecessary taxes. Our accountants analyze your case and recommend the best option.
Need help registering your RFC or choosing the right tax regime?
Our accountants help you register correctly with SAT, select the most advantageous tax regime and avoid costly mistakes from day one. Service in Spanish, English and Russian.
Free consultation →