U.S.-Mexico Tax Treaty: What It Covers and How It Applies

The United States and Mexico have had an income tax treaty in effect since 1994. For individuals and businesses with operations or income on both sides of the border, understanding what the treaty does, and what it does not do, is often the difference between correct planning and expensive mistakes.

What the Treaty Does

The U.S.-Mexico Income Tax Treaty is designed to prevent double taxation and reduce withholding rates on cross-border income flows. At a high level, it does three things:

• Limits how much each country can withhold from income paid to residents of the other country,
• Provides tie-breaker rules when a person could be taxed as a resident of both countries, and
• Establishes a framework for exchange of tax information between the two governments.

The treaty does not override U.S. domestic law in most cases, it sets ceilings, not floors. If the U.S. domestic rate is already lower than the treaty rate, the lower domestic rate applies.

Residency and the Tie-Breaker Rules

The treaty applies based on where a person is a “resident.” For most purposes, a person is a resident of the country where they pay tax by reason of domicile, permanent home, or place of incorporation.

When someone qualifies as a resident of both countries, common for dual nationals, long-term visa holders, or business owners with operations in both, the treaty provides tie-breaker rules applied in this order:

1. Permanent home: the person is a resident of the country where they have a permanent home available
2. Center of vital interests: closer personal and economic ties
3. Habitual abode: where the person spends more time
4. Nationality: the person is a resident of the country of which they are a national
5. Mutual agreement: the two countries resolve it between themselves

For U.S. citizens, the tie-breaker rules have limited practical effect because the U.S. taxes its citizens on worldwide income regardless of residency. A U.S. citizen who is also a Mexican resident cannot use the treaty to become a “non-U.S. resident” for tax purposes.

Withholding Rates on Key Income Types

One of the most practical uses of the treaty is reducing Mexican withholding on U.S.-source income paid to Mexican residents, and vice versa.

These rates apply to payments from one country to residents of the other. If a Mexican company pays dividends to a U.S. shareholder, the 10% or 15% treaty rate replaces Mexico’s higher domestic withholding rate, but the U.S. shareholder still reports the income on their U.S. return and claims a foreign tax credit for taxes paid to Mexico.

Capital Gains

Capital gains treatment under the treaty is more nuanced than passive income. The general rule is that gains are taxable only in the country of residence, but there are important exceptions:

• Real property: Gains from selling real property located in a country may be taxed in that country. A Mexican resident selling U.S. real estate may owe FIRPTA withholding in the U.S. regardless of the treaty.
• Business property: Gains attributable to a permanent establishment (PE) may be taxed where the PE is located.
• Company interests: Gains from selling shares of a company that derives most of its value from real property located in one country may be taxable in that country.

FIRPTA applies to foreign persons selling U.S. real property interests. The treaty does not eliminate FIRPTA withholding for Mexican residents, it may reduce it in certain circumstances, but the withholding requirement still applies at the point of sale.

Permanent Establishment

If a Mexican business operates in the U.S. without a formal U.S. entity, it may still have a “permanent establishment” (PE), a taxable presence, under the treaty. A PE generally exists when:

• The business has a fixed place of business in the U.S. (office, factory, workshop), or
• An agent in the U.S. regularly closes contracts on behalf of the foreign enterprise.

Having a U.S. PE means the business owes U.S. tax on income attributable to that establishment, even without a U.S. corporation or LLC. Many foreign businesses are unaware of this exposure until they face a U.S. filing requirement.

The Totalization Agreement

Separate from the income tax treaty, the U.S. and Mexico have a Totalization Agreement that coordinates Social Security coverage for workers who move between the two countries.

Under the agreement:

• A worker is generally covered by only one country’s social security system at a time,
• U.S. workers sent to Mexico by a U.S. employer remain covered by U.S. Social Security for up to five years,
• Mexican workers in the U.S. follow similar rules under Mexico’s IMSS system, and
• Contribution periods in both countries can be combined to qualify for retirement benefits.

This matters practically for business owners and employees who split time between countries and would otherwise face dual contributions.

How the Treaty Interacts with FBAR and FATCA

The treaty does not reduce or eliminate U.S. reporting requirements for foreign financial accounts and assets. A U.S. person with Mexican bank accounts, investment accounts, or ownership interests in Mexican entities still owes:

• FBAR (FinCEN 114): Required when aggregate foreign financial account balances exceed $10,000 at any point during the year
• Form 8938 (FATCA): Required for specified foreign financial assets above threshold amounts
• Form 5471 / Form 8865: Required for ownership in Mexican corporations or partnerships above certain thresholds

These forms are separate from the income tax return and are not affected by treaty provisions. Failure to file carries significant penalties, the treaty offers no protection there.

Common Planning Situations

Mexican investor buying U.S. real estate: Subject to FIRPTA withholding at sale, must file a U.S. return, may owe U.S. tax on rental income. The treaty can reduce withholding on certain income types but does not eliminate U.S. filing obligations.

U.S. citizen living in Mexico: Must file a U.S. return reporting worldwide income, can claim a foreign tax credit for Mexican taxes paid, may use the Foreign Earned Income Exclusion if qualifying tests are met. The treaty’s tie-breaker rules do not override U.S. citizenship taxation.

Mexican company paying royalties to a U.S. licensor: Treaty reduces Mexican withholding on royalties to 10%. The U.S. company reports the gross royalty income and claims a foreign tax credit for the Mexican tax withheld.

U.S. business expanding into Mexico: Must assess whether a PE exists in Mexico before the first contract is signed. Operating through a Mexican subsidiary avoids the PE issue but creates different compliance requirements.

Related Articles

• Pre-Immigration Tax Planning: What to Do Before Moving to the U.S.
• Foreign-Owned U.S. LLC: Investment Structures and Tax Treatment
• U.S. Tax for Latin American Families with U.S. Ties

Last updated: 2026