Capital Gains Tax When Selling Property in Mexico

Every seller eventually asks the same question: how much of the sale price actually gets taxed away? In Mexico, the answer depends heavily on your residency status, your paperwork, and which of two calculation methods gets applied at closing — and the difference between them can be tens of thousands of dollars. It's one of the most consequential financial decisions in the entire ownership lifecycle, and it's largely decided by preparation done long before the sale itself.

How ISR on Capital Gains Actually Works

Mexico taxes capital gains on real estate through ISR (Impuesto Sobre la Renta, or income tax). Unlike in the US or Canada, this tax is typically withheld and remitted at closing by the notario público — the licensed legal official who oversees the transfer of title — rather than settled later when you file an annual return.

The Two Withholding Methods for Non-Resident Sellers

Non-resident foreign sellers can generally have the notario apply one of two calculation approaches:

Method	How It's Calculated	Best For
Flat rate on gross price	25% of the total sale price, no deductions allowed	Sellers with little or no documentation of original cost/improvements
Net gain method	35% of the gain after deducting documented acquisition cost, verified improvements, and eligible closing costs like commission and notario fees	Sellers who can document their original purchase price and improvement costs

The net-gain method almost always produces a lower tax bill if you actually have the paperwork — original deed, invoices (facturas) for renovations, and commission and notario cost records — but the notario needs that documentation in hand at closing, not after.

A Simple Illustration

Imagine a seller who originally paid $250,000 USD for a condo and sells it years later for $400,000 USD, with $30,000 in documented improvements and closing costs. Under the flat method, the tax is calculated on the full $400,000 sale price. Under the net-gain method, it's calculated on roughly $120,000 ($400,000 minus $250,000 minus $30,000). Even at a higher percentage rate, taxing a much smaller base typically produces meaningfully lower total tax — which is exactly why documentation is worth the effort well before a sale is even on the horizon.

Why an RFC Matters More Than People Expect

An RFC (Registro Federal de Contribuyentes, Mexico's tax ID number) isn't strictly required to complete a sale, but without one the notario has limited ability to verify your deduction eligibility, which often pushes the default toward the higher flat-rate withholding. If you know you'll sell within the next year or two, getting an RFC in place ahead of time gives the notario more room to apply the net-gain calculation properly.

The Primary Residence Exemption — And Why Most Foreign Sellers Don't Qualify

Mexican tax residents who have used a property as their primary residence for at least three years, and who haven't claimed the exemption on another property sale that year, can exclude gains up to roughly 700,000 UDIs (a Mexican inflation-indexed unit, working out to roughly MXN 5-6 million as of 2026) from ISR. That's a meaningful exemption — but it applies to tax residents of Mexico, verified through RFC records, utility bills, and other proof of residency, not simply to owners who spend part of the year there. Most US and Canadian owners hold non-resident status for Mexican tax purposes and don't qualify for this exemption, regardless of how much time they personally spend in the home.

Don't Forget the Home-Country Side

Selling in Mexico doesn't end your tax obligations back home. US citizens and green card holders generally must report the gain on their US return regardless of where the property sits, though a foreign tax credit (via Form 1116) can often offset Mexican tax paid against US liability. Canadian residents likewise report worldwide capital gains to the CRA and may claim a foreign tax credit for ISR paid in Mexico. Neither system is something to navigate on assumptions — both call for an accountant familiar with cross-border property sales.

If your property was held through a fideicomiso, US taxpayers should also be aware of the ongoing reporting history around that structure. The IRS has clarified, in guidance including Revenue Ruling 2013-14, that a standard Mexican real estate trust used purely to hold title for a foreign owner generally isn't treated as a foreign trust requiring the more burdensome foreign trust reporting — but related account and asset disclosures, such as FBAR reporting for any Mexican bank accounts and Form 8938 for specified foreign assets, can still apply depending on your overall financial picture. This is a narrow, fact-specific area of US tax law, and confirming your specific situation with a cross-border accountant before and after a sale is worth the modest cost.

Start collecting your original purchase deed, avalúo (appraisal), and any renovation invoices as soon as you're even considering a sale — not the week before closing. Missing documentation is the single biggest reason sellers end up paying the higher flat-rate ISR.

Frequently Asked Questions

Q: Who actually pays the capital gains tax — buyer or seller?

A: The seller bears the ISR liability, but it's withheld and remitted by the notario at closing, so it comes directly out of sale proceeds rather than being billed separately afterward.

Q: Can I reduce my ISR by proving I renovated the property?

A: Yes, but only with proper facturas (official tax invoices) for the work — receipts or contractor estimates without formal invoicing generally won't be accepted as deductions.

Q: Does owning through a fideicomiso change how capital gains tax is calculated?

A: No. The fideicomiso is a title-holding structure; the ISR calculation is based on your residency status and documentation, not on how title is held.

Q: What if I lost my original purchase documents over the years?

A: Talk to your notario as early as possible — in some cases prior deed and closing records can be reconstructed through the Public Registry of Property, though this takes time and is far easier to sort out before you're under contract to sell than during a live transaction.

Every seller's documentation and residency situation is different, and getting it right before you list can materially change your net proceeds. Top Listings Riviera Maya works alongside notarios and accountants regularly and can help you get organized ahead of a sale — call +44 7513 075054 to start the conversation early.