Selling Your Home in Mexico as a Foreigner: Get Your RFC Before You List

Every year foreign owners in Rosarito sign a sales contract, arrive at the notary's office, and learn that a large slice of the price is about to be withheld as Mexican income tax (ISR). In most of those cases the tax was avoidable. What was missing was not money or a clever structure — it was paperwork that takes weeks to obtain and cannot be produced on closing day: an RFC, proof of Mexican tax residency, and household bills in the seller's name.

The exemption: your home can be sold free of ISR

Mexico's Income Tax Law (Ley del ISR, article 93, section XIX, paragraph a) exempts an individual's gain on the sale of their casa habitación — their own home. The main conditions are:

• The exemption covers a sale price of up to 700,000 UDIS per seller. The UDI is an inflation-indexed unit whose peso value changes daily, so the notary calculates the ceiling on the day of closing. Any part of the price above the ceiling is taxed proportionally.
• The seller must not have used the same exemption on another home during the previous three years.
• The sale must be formalized before a notario público, who is the one that applies the exemption and answers for it to the tax authority (SAT).

It applies whether you hold title directly or, as most foreigners on the coast do, through a bank trust (fideicomiso).

Who qualifies: Mexican tax residents with an RFC

The exemption is for individuals who are tax residents of Mexico. Citizenship does not matter — a U.S. or Canadian citizen whose home is in Mexico can be a Mexican tax resident — but the notary cannot simply take your word for it. Under the SAT's current administrative rules, the deed must record your sworn statement that you are a Mexican tax resident, your tax domicile, and your RFC (Registro Federal de Contribuyentes, the Mexican taxpayer ID), supported by a document such as a tax residency certificate (constancia de residencia fiscal) or your tax ID card (cédula de identificación fiscal).

No RFC, no exemption. And an RFC is not something you can get the morning of closing: it requires an appointment with the SAT, a valid immigration document and proof of address.

Proving the house is really your home

The regulations to the Income Tax Law (article 155) list what the notary may accept as proof that the property is your home. For foreign owners, who do not have a Mexican voter ID, that means in practice:

• Utility bills for the property — electricity or telephone — or
• Bank or store-card statements showing the property's address,

issued in the name of the seller, the seller's spouse, or their direct ascendants or descendants.

This is where many sales go wrong. The electricity account is still in the name of the developer, the previous owner or a property manager. Notaries commonly ask for the electricity bill as an official tax receipt (CFDI) issued in your name and with your RFC on it — so the practical sequence is: get the RFC, then put the CFE account in your name with that RFC, and let bills accumulate before you put the house on the market.

What it costs when the exemption is not available

If you cannot meet these requirements, the notary must calculate and withhold ISR at closing. How much depends on your status:

• Non-residents of Mexico for tax purposes. The general rule (article 160) is 25% of the total sale price, with no deductions at all. Alternatively, if you appoint a representative in Mexico who meets the legal requirements and the sale is recorded in a public deed, you may choose to pay 35% of the gain instead.
• Mexican tax residents who do not qualify (no acceptable proof of home, a second exempt sale within three years, or the portion above the UDI ceiling). The tax is calculated on the gain, at progressive rates that reach 35%.

The low-purchase-price trap

"Gain" is not what you feel you made. It is the sale price minus the deductions the law allows — chiefly your documented acquisition cost as recorded in your deed or fideicomiso, adjusted for inflation, with the construction portion depreciated for each year you held it.

For years it was common in Baja California to record a purchase at a fraction of the real price, or to take over a trust or a lot with little or no price stated. That decision comes due at the sale: with a very low recorded cost, almost the entire sale price is treated as gain. The law sets a floor — the cost is deemed to be at least 10% of the sale price — which means that up to 90% of what the buyer pays can be taxable.

Two things reduce the damage, and both depend on the RFC:

1. Improvements and construction are deductible only with official invoices (CFDI) issued to you — which a contractor can only issue to your RFC.
2. Notary fees, transfer taxes and the sales commission you pay are also deductible when properly invoiced.

What to do before you list

1. Confirm your tax residency position with counsel. Becoming a Mexican tax resident has consequences beyond this sale, and citizens of other countries may still owe tax at home.
2. Obtain your RFC and keep your tax status certificate current.
3. Put the electricity account in your name, with your RFC, at the property's address. Do the same with a Mexican bank statement if you can.
4. Gather your acquisition deed or fideicomiso and every invoice for construction and improvements.
5. Ask your attorney to run the ISR calculation both ways — exempt and not exempt — before you agree on a price or sign a promissory contract.

Started three to six months before the sale, this is routine. Started the week of closing, it is usually too late.

This article is general information, not tax advice; the SAT's administrative rules are reissued every year and each sale turns on its own documents. Rosarito Legal helps foreign owners in Playas de Rosarito and across Baja California prepare for a sale — RFC registration, exemption paperwork, and coordination with the notary — in English and Spanish. Talk to us before you list, not after you have a buyer.

Related sites from the same firm: Galarza Legal for legal representation across Baja California, and Mexico Trust Services for fideicomiso matters.