If you have a bank account in Guadalajara, a house in Baja California, a 401(k) in San Diego and parents or children on both sides of the border, you aren't managing two sets of finances. You're managing one financial life that happens to touch two countries. The challenge is that each country looks at that life through its own rules.

Here is a practical way to think it through.

Start With a Map of Everything You Own

Before any strategy, it helps to see the whole picture in one place. List every account and asset, which country it's in, whose name it's in, and roughly what it's worth:

  • Bank and investment accounts in the U.S. and in Mexico
  • Retirement accounts, such as a 401(k), IRA or a Mexican Afore
  • Real estate in either country, and how each property is titled
  • Business interests, and where each business is organized
  • Life insurance policies and who the beneficiaries are

Many families have never seen all of this on one page. Once you do, the questions that matter tend to become obvious: which accounts need to be reported, which documents are missing, and where the plan is out of balance.

Know Where You Are a Tax Resident

Residency drives almost everything else. The U.S. taxes its citizens and residents, including green card holders, on their worldwide income, no matter where they live. Mexico also taxes its tax residents on worldwide income. Mexican residency generally depends on where you have your home and, if you have one in both countries, where your center of vital interests is.

That means some people are treated as residents of both countries at the same time. The U.S.–Mexico tax treaty has rules for deciding which country gets the first claim, and foreign tax credits are designed to help avoid paying tax twice on the same income. But those protections only work if both returns are prepared with the other country in mind. If you are planning a move in either direction, the timing of that move is worth discussing with tax professionals before it happens.

Stay Current on U.S. Reporting

U.S. reporting rules surprise many families because they apply even when no tax is owed.

  • FBAR (FinCEN Form 114). U.S. persons generally must file it if the combined value of their foreign financial accounts is more than $10,000 at any time during the year.
  • Form 8938 (FATCA). Foreign financial assets may also need to be reported with your tax return. The thresholds are higher and depend on your filing status and whether you live in the U.S. or abroad.
  • Foreign investment funds. Many non-U.S. mutual funds, including funds commonly offered by Mexican banks, can be treated as passive foreign investment companies (PFICs) under U.S. tax rules. That brings extra reporting and often less favorable tax treatment.

Penalties for missing these filings can be significant, so it's worth confirming each year with your tax preparer what applies to you.

Think About Where Your Accounts Are Held

Where an account is held can matter as much as what's in it. Some U.S. brokerage firms and banks limit services for customers who live outside the U.S., which can become an issue if you retire in Mexico. Holding money in pesos and dollars also means exchange rates affect your plan, from your monthly budget to the income you expect in retirement.

There's no single right answer. The point is to decide on purpose, based on where you live, where you spend and where your family is, rather than letting accounts accumulate wherever they happened to be opened.

Make Your Estate Plan Work in Both Countries

A U.S. will or living trust may not work smoothly for property in Mexico, and Mexican law has its own rules for wills and heirs. Many families work with an attorney in the U.S. and a notario in Mexico so the documents in each country fit together instead of contradicting each other.

Property deserves special attention. Foreign nationals who buy residential property in Mexico's restricted zone, within 100 kilometers of the border or 50 kilometers of the coast, generally hold it through a bank trust (fideicomiso). How that trust names beneficiaries affects what happens to the property later.

Beneficiary designations on U.S. accounts and insurance policies also matter, especially when an heir lives in Mexico or a spouse is not a U.S. citizen. Rules that apply automatically between U.S. citizen spouses may work differently in that case.

Coordinate Your Professionals

Most cross-border problems don't come from one bad decision. They come from professionals in each country doing good work without knowing what the other side is doing. A CPA in San Diego may not know about an account in Monterrey. A notario in Mexico may not know how a U.S. trust is set up.

A financial planner can help keep the whole picture organized and make sure your CPA or enrolled agent, your contador and your attorneys are working from the same information. That coordination is often where the most value is.

Revisit the Plan When Life Changes

A cross-border plan is not a one-time project. Moving, selling a property, receiving an inheritance, starting a business or a child going to college in the other country can each change the picture. A quick review at those moments helps keep small issues from becoming expensive ones.

If you'd like to talk through your own situation, in English or Spanish, you can learn more about our cross-border wealth management approach, see how The Crossing works, or contact us.