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    Mexico Capital Gains Tax Calculator for Americans (2026)

    Estimate the Mexican ISR you'll owe on the sale of your Mexico property. Adjust the inputs, see both the flat-rate and net-gain methods, and find out if the primary residence exemption could apply to you.

    📅 May 2026⏱ 6 min read + calculator

    If you're an American selling property in Mexico, your Mexican capital gains tax (ISR) bill is usually computed two ways — and the notario uses whichever produces less tax. This calculator gives you a fast, plain-English estimate of both methods, plus checks whether the primary residence exemption could wipe out most of the bill.

    What this calculator is not: a substitute for your notario or a cross-border tax advisor. ISR brackets shift annually, peso/dollar FX moves, and your facts may not fit the model. Use the result as a starting point for the conversation.

    Need a real number before you list? We coordinate Mexico ISR planning with U.S. CPAs who handle the IRS side. Get a free consultation →

    The Calculator

    Estimated Mexican ISR

    Method A: 25% flat
    $70,000
    25% of gross sale price
    Method B: net gain
    Requires RFC
    ~22% non-resident on $95,000 net gain
    Your likely Mexican tax bill
    $70,000
    Flat 25% (Method A) is your default without RFC or deductible documentation.

    Estimates are illustrative. Real ISR is computed by your notario in pesos using SAT brackets on the date of closing, with adjustments for inflation indexing (INPC). Primary residence exemption cap shown at ~$325K USD reflects approximately 5.85M pesos at recent FX.

    How Mexican Capital Gains Tax Works

    When you sell property in Mexico as a foreign owner, the notario público calculates your Mexican income tax (ISR — Impuesto Sobre la Renta) using one of two methods, and applies the lesser:

    • Method A — 25% flat on gross sale. No deductions. Simple, but punishing on properties with significant cost basis or improvements. This is the default when the seller has no RFC, no deductible records, or doesn't qualify as a Mexican tax resident.
    • Method B — progressive rate on net gain. Allows deduction of original purchase price (indexed for inflation), documented improvements (with facturas), and selling costs (commission, fideicomiso closure, notario fees on the sale side). Net gain is taxed at progressive rates that effectively land around 18–22% for most American sellers.

    The choice isn't actually yours — the notario applies the lower figure automatically. But what you can control is whether Method B is even available to you, which depends on documentation.

    What Makes Method B Available

    To use the net-gain method, you generally need:

    • A Mexican RFC. The tax ID is non-negotiable. Without it, you default to the 25% flat rate. Here's how to get one.
    • The original escritura showing the purchase price you paid.
    • Facturas (official tax invoices) for any improvements you want to deduct. A receipt isn't a factura — only documents with your RFC and proper SAT formatting count.
    • Selling-side documentation: commission invoices, fideicomiso closure fees, notario costs on your side of the closing.

    The Primary Residence Exemption

    If the property is your primary residence and you can prove it, you may exempt up to roughly $325,000 USD of gain from Mexican ISR (equivalent to approximately 5.85 million pesos at recent FX). The cap is set in pesos and adjusted periodically.

    To qualify, all of the following must be true:

    • You have Mexican tax residency (temporary or permanent INM card, plus tax residency status).
    • You hold a Mexican RFC.
    • You've occupied the property as your primary residence for at least 3 years (with documentation — utility bills in your name, CFE bills, etc.).
    • You haven't claimed this exemption on another Mexican property sale in the last 3 years.

    The exemption is the single largest ISR-reduction lever available to American sellers. If you're planning a sale 1–3 years out, this is the case for getting Mexican residency and an RFC before you list.

    Read more: Mexico's Primary Residence Capital Gains Exemption explained.

    U.S. Tax on a Mexico Sale

    The Mexican ISR is only half the story. As a U.S. citizen, you also report the sale on your U.S. tax return — typically on Form 8949 / Schedule D for capital gains. The IRS taxes worldwide income.

    The good news: you can claim a Foreign Tax Credit (Form 1116) for the Mexican ISR you paid, which usually offsets most or all of the U.S. capital gains tax on the same income. In simple cases, the total tax bill ends up being approximately the higher of the two countries' rates — not the sum.

    Run the calculator above, then take the result to a U.S. CPA who handles foreign-source income before you sign anything binding.

    Frequently Asked Questions

    Is the calculator's number what I'll actually pay?
    Use it as a sanity check, not a final figure. Real ISR is computed in pesos by your notario at closing, using the official SAT brackets, the INPC inflation index, and the current peso/dollar FX. The estimate above usually lands within ±15% of the real number for typical American sellers.
    Can I deduct improvements I paid for in cash without facturas?
    Generally, no. To deduct an improvement under Method B, you need a factura — an official SAT-formatted electronic invoice — issued at the time the work was done, with your RFC on it. Cash receipts and informal invoices are not accepted by the notario for ISR purposes.
    What if I don't have an RFC and I'm about to sell?
    Getting an RFC takes 2–6 weeks if you can travel to the SAT office. If your sale is imminent and the deal is small, the 25% flat rate may simply be cheaper than delaying. If the gain is large or you'd qualify for the primary residence exemption, the wait is almost always worth it.
    Does the calculator account for inflation indexing (INPC)?
    Not directly — Mexican tax law allows the original purchase price to be indexed upward by the INPC (consumer price index) to reduce the taxable gain. The estimate above is conservative (no INPC adjustment), so your actual Method B figure may be slightly lower than what you see here.
    How is the notario chosen and when does ISR get paid?
    Either party can propose the notario, but the buyer typically picks (since they pay most of the notario's fee). ISR is withheld by the notario at closing and remitted directly to the SAT — you don't pay it later. Your wire from the closing is net of the tax.
    Can my U.S. losses on other investments offset Mexican capital gains?
    Yes — on the U.S. side. U.S. capital losses can offset U.S. capital gains, including the gain from a Mexico property sale, on your Form 1040. They cannot reduce your Mexican ISR.

    Next Steps

    • Pull the original escritura and confirm the purchase price recorded there matches what you actually paid.
    • Inventory your improvement facturas. Anything without a proper factura is, for ISR purposes, not deductible.
    • If you'd qualify for the primary residence exemption with another 6–24 months of effort (residency + RFC + occupancy documentation), run the math both ways.
    • Get a U.S. CPA who has handled at least one Mexico property sale on board before you accept an offer.
    • Read the related guides: How to sell your Mexico property as a U.S. citizen, how to sell remotely, and seller closing costs explained.

    Ready to talk it through?

    Our bilingual team helps American buyers and sellers navigate Mexico real estate end-to-end.

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