You Own a Company in Mexico. Does the IRS Need to Know?

Owning a business outside the United States can create U.S. tax and reporting obligations—even when the company operates entirely abroad, keeps its money abroad, and already pays foreign taxes.

Imagine this.

You started a company in Mexico several years ago. Maybe it is a transportation company in Nuevo Laredo, a manufacturing business in Monterrey, a medical practice, a real estate company, or a family business you built long before moving to the United States.

The company has Mexican employees and customers. Its bank accounts are in Mexico. Its accounting is maintained in Mexico. It files Mexican tax returns and pays Mexican taxes. And perhaps most importantly, the money stays in Mexico.

So when you become a U.S. resident—or if you were already a U.S. citizen—you might reasonably ask: “What does my Mexican company have to do with my U.S. tax return?”

Potentially, quite a lot.

One of the biggest misconceptions in international tax is that a foreign business does not matter to the IRS unless money is transferred to the United States. That is not necessarily true. Depending on your U.S. tax status, ownership percentage, the type of entity, the other owners, and the company's activities, U.S. reporting requirements may exist even if you never transfer a dollar to the United States.

First Question: Are You a U.S. Taxpayer?

The first step is determining whether the owner is subject to the U.S. tax system. U.S. citizens and U.S. resident aliens are generally taxed on worldwide income.

Imagine Carlos has lived in Monterrey most of his life and owns 70% of a successful Mexican corporation. He later becomes a U.S. permanent resident and moves to Texas. The Mexican company has not changed, but Carlos's relationship with the U.S. tax system has.

Once Carlos becomes subject to U.S. taxation on worldwide income, his foreign company may need to be analyzed under U.S. international tax rules. This is why cross-border planning can be especially valuable before someone becomes a U.S. tax resident.

“But My Company Already Pays Taxes in Mexico.”

This is an understandable question. If the business earned its income in Mexico and already paid Mexican taxes, why should the United States care?

The answer is that the U.S. and Mexican tax systems are separate. U.S. tax law contains mechanisms that can help address double taxation, including foreign tax credits, and the United States and Mexico have an income tax treaty. But paying tax in Mexico does not automatically eliminate U.S. filing requirements.

It is also important to separate taxation from information reporting. You can have a U.S. reporting requirement even when a transaction ultimately produces little or no additional U.S. income tax. That matters because international information returns can carry substantial penalties when a required form is not properly filed.

Meet Form 5471

For many U.S. taxpayers who own interests in foreign corporations, Form 5471 is one of the most important international information returns.

Depending on the applicable filing category, Form 5471 can require information about ownership, changes in ownership, the company's income statement and balance sheet, earnings and profits, distributions, related-party transactions, foreign taxes, Subpart F income, GILTI, and other international tax items.

Not every foreign shareholder has identical requirements. The applicable filing category and schedules depend on the facts, which is why ownership percentages and relationships among the owners matter.

Your Ownership Percentage Matters

Imagine four siblings own a Mexican family business. One owns 5%, another 15%, another 30%, and the fourth 50%.

They own the same company, but their U.S. tax reporting may not be identical.

Certain U.S. international tax rules use important ownership thresholds. A 10% interest can matter for some provisions, while more-than-50% U.S. ownership can be important when determining whether a foreign corporation is a Controlled Foreign Corporation, or CFC.

The analysis can also include direct, indirect, and constructive ownership. In other words, saying “I only own 40%” does not always end the conversation. Family relationships and ownership through other entities can matter under the applicable attribution rules.

What Is a Controlled Foreign Corporation?

A Controlled Foreign Corporation, commonly called a CFC, is a U.S. tax classification. It does not mean the company has done anything wrong.

In general terms, a foreign corporation can be a CFC when more than 50% of its stock, measured by vote or value, is owned by qualifying U.S. shareholders under the applicable direct, indirect, and constructive ownership rules.

CFC status matters because it can trigger additional reporting and U.S. income inclusion rules for certain U.S. shareholders.

You May Have U.S. Taxable Income Without Receiving the Money

Imagine your Mexican company earns $500,000. After expenses and Mexican taxes, you leave the remaining cash inside the company to buy equipment, hire employees, purchase trucks, expand a warehouse, or increase inventory.

You personally receive zero dollars.

It is natural to think, “I didn't receive a dividend, so I don't have U.S. income.”

International taxation is not always that simple. Certain anti-deferral rules can cause a U.S. shareholder to recognize income connected to a CFC even though the company did not distribute the cash. Two important concepts in this area are Subpart F income and GILTI.

GILTI: The Tax Concept That Surprises Foreign Business Owners

GILTI stands for Global Intangible Low-Taxed Income. The name can be misleading because people often assume it applies only to technology companies, intellectual property, or tax-haven structures.

A normal operating company in Mexico can potentially create a GILTI inclusion for a qualifying U.S. shareholder.

The calculation is technical and depends on several tax attributes. But the basic idea business owners need to understand is simple: the U.S. tax system can potentially require you to recognize income connected to a foreign corporation before the company actually distributes that money to you.

That is why international tax planning should happen before tax-return season whenever possible.

What About Section 962?

For certain individual U.S. shareholders of CFCs, a Section 962 election can become an important planning consideration.

Depending on the facts, the election can change how certain CFC income is taxed and how certain foreign taxes are treated. It is not an automatic election that every foreign business owner should make.

The current-year benefit and the potential future tax consequences when earnings are distributed should be modeled before making the decision.

“What If I Never Take Money Out of Mexico?”

Keeping money outside the United States does not necessarily eliminate U.S. tax reporting.

U.S. citizens and resident aliens are generally subject to a worldwide-income system. The location of the bank account is not, by itself, what determines whether income or an ownership interest must be reported.

A Mexican company's profits do not automatically become invisible to the U.S. tax system simply because the money stays in a Mexican bank account.

Don't Forget About Foreign Bank and Financial Accounts

The foreign company may only be one part of the reporting picture.

Foreign accounts can create separate requirements, including the FBAR. Generally, an FBAR requirement can arise when a U.S. person has a financial interest in or signature authority over qualifying foreign financial accounts whose aggregate value exceeds $10,000 at any time during the calendar year, subject to the applicable rules and exceptions.

The word aggregate matters. Three accounts holding $4,000, $4,500, and $3,000 do not individually exceed $10,000, but together they reach $11,500.

Form 8938 may also apply depending on the taxpayer and applicable thresholds. FBAR and Form 8938 are separate reporting regimes, so filing one does not automatically satisfy the other.

What If the Company Is an S.A. de C.V.?

This question is particularly relevant for U.S.–Mexico business owners.

A Sociedad Anónima de Capital Variable, or S.A. de C.V., is common in Mexico. A business owner may assume that because Mexico calls it a corporation, the United States will automatically treat it exactly the same way.

Foreign entity classification for U.S. federal tax purposes has its own rules. The entity's legal characteristics and applicable U.S. classification rules need to be reviewed before determining the proper reporting.

This is another reason planning before becoming a U.S. taxpayer—or before changing an existing foreign structure—can be valuable.

What If the Foreign Business Is a Partnership Instead?

Not every foreign business interest belongs on Form 5471.

If a foreign business is treated as a partnership for U.S. tax purposes, Form 8865 may become relevant. Form 8865 has its own filing categories, ownership rules, and reporting requirements.

That is why “I own a business in Mexico” is only the beginning. Your CPA needs to understand what you own, who owns it with you, and how the entity is classified for U.S. federal tax purposes.

The $10,000 Question: “What Happens If I Didn't File?”

International information-reporting penalties can become serious quickly.

Certain failures to timely file a required Form 5471 can result in an initial $10,000 penalty per form, per year, with additional consequences potentially applying in some circumstances.

Imagine someone has filed a Form 1040 every year and believes everything is current. Their wages, investments, and deductions were reported, but nobody ever addressed the foreign corporation.

The taxpayer may have filed a U.S. income tax return while still having an unresolved international reporting issue. If you discover a potential problem, the right first step is to understand exactly what should have been filed before deciding how to correct it.

“My Previous CPA Never Asked Me.”

This happens more often than many people expect.

Sometimes the taxpayer did not realize foreign ownership was relevant. Sometimes the preparer did not specialize in international reporting. Sometimes everyone assumed that because the business already had a Mexican accountant, the U.S. accountant did not need to know about it.

Discovering a potential filing issue does not mean you should start filing random forms. First determine what entity exists, who owned it during each year, when the taxpayer became subject to U.S. taxation, what income and distributions occurred, whether there were related-party transactions, what foreign taxes were paid, and which U.S. international rules actually applied.

International compliance problems should be diagnosed before they are treated.

What Documents Should You Give Your CPA?

If you own a foreign company, give your CPA enough information to understand the complete picture.

Useful records can include formation documents, shareholder records, ownership percentages, acquisition dates, financial statements, trial balances, Mexican tax returns, foreign taxes paid, dividend history, capital contributions, shareholder loans, intercompany and related-party transactions, foreign bank account information, and prior U.S. international information returns.

Having a Mexican accountant does not replace the U.S. international tax analysis. Ideally, the professionals work together: the Mexican accountant understands the local books and filings, while the U.S. CPA determines how those activities need to be treated and reported in the United States.

Planning Before Moving to the United States Can Make a Huge Difference

Consider two business owners. Both own successful companies in Mexico and both plan to become U.S. residents.

Business Owner A meets with an international tax CPA before moving. The ownership structure, entity classification, historical earnings, foreign accounts, and potential CFC and GILTI issues are reviewed in advance.

Business Owner B moves first. Three years later, someone preparing the U.S. return finally asks, “Do you own any companies outside the United States?”

The answer is yes, but now everyone is looking backward instead of planning forward.

When international tax is involved, timing matters.

Your Mexican Accountant and U.S. CPA Should Not Work in Separate Worlds

For cross-border business owners, tax compliance frequently involves professionals in both countries.

A transaction can be completely normal under Mexican accounting and tax rules while still creating a separate U.S. reporting requirement. Problems arise when the U.S. preparer never learns that the transaction or foreign ownership exists.

At LUNA CPA, our approach is to understand the complete structure—not simply prepare one isolated form. We want to know who owns what, where the entities operate, how money moves among owners and companies, and how those activities interact with U.S. reporting requirements.

A Simple Question Can Reveal a Complicated Tax Situation

Let's return to the original scenario.

You own a company in Mexico. It operates entirely in Mexico. It pays Mexican taxes. Its employees are in Mexico. Its money stays in Mexico.

Does the IRS need to know?

If you are a U.S. citizen or U.S. tax resident, the answer may very well be yes.

That does not automatically mean you owe additional U.S. tax. It means the ownership, entity classification, income, accounts, and transactions should be reviewed before assuming there is nothing to report.

International tax is rarely about one isolated form. The goal is to understand the complete picture and make sure the U.S. reporting matches the taxpayer's actual foreign activities.