Do I file in both US and Mexico?
Usually yes, at least for the transition year. US persons with Mexican property need the trust arrangement characterised; cross-border manufacturing raises transfer pricing and permanent establishment in both directions.
Which return do you prepare first?
Whichever one the credit depends on. Preparing them in the wrong order is the most common reason a credit is claimed in the wrong place, and it is also the most common reason a client ends up paying twice and reclaiming later.
Does the treaty mean I only file once?
No. A treaty allocates the tax; it does not consolidate the filing. Both obligations survive, and in some cases the treaty position itself has to be disclosed on a return before it can be relied on.
What about sub-national tax — states and provinces?
They set their own residency and sourcing rules and are not bound by the federal treaty in the same way. A position that is protected federally can still produce a state or provincial return, which is the single most common surprise in this corridor.
Can you work with my adviser in the other country?
That is how most corridor engagements run. They keep their side, we take ours and the interaction between the two, and the scope boundary is agreed in writing so nothing is duplicated or dropped.
What if I am behind in one country and current in the other?
That is the usual pattern. We map the unfiled years first and check which catch-up routes are open before anything is filed, because the route chosen for one year affects the relief available for the rest.
Does my Mexican bank trust count as a trust for US reporting?
That is exactly the question, and it has to be answered before anything is filed. Foreign buyers commonly hold Mexican property through a bank trust arrangement, and how that arrangement is characterised at home decides whether you are treated as owning property or as holding an interest in a trust. The two lead to entirely different reporting, and the difference is not cosmetic — one is a line on a return, the other can carry obligations of its own. We read the trust deed and the purchase documents before offering a view, because the characterisation drives every year that follows.
I bought a house in Mexico — what do I have to report?
Start with how you hold it. Property bought by a foreign buyer is frequently held through a bank trust arrangement, and until that arrangement is characterised you cannot know whether the reporting is about real estate or about an interest in a trust. After that the answers follow in order: the income the property produces while you hold it, reported in both countries with relief claimed for the tax borne in Mexico, and then the eventual disposal. Put the acquisition documents somewhere safe now, because the cost history is what the sale computation will rest on.
Does my company have a permanent establishment in Mexico?
It depends on what your people actually do there, not on whether anything has been registered. The usual triggers are a fixed place through which the business is carried on, and personnel who play the principal role leading to the conclusion of contracts. Both are questions of fact, decided on evidence — contracts, job descriptions, who negotiates and who signs. This runs in both directions in this corridor: a Mexican group with staff in the United States faces the same analysis mirrored. Settle it before the arrangement is built, because it is far harder to unwind afterwards.
Do we need transfer pricing documentation for our Mexican plant?
If goods, services, financing or intangibles move between related entities across this border, the pricing has to be defensible in both countries, and defensible means documented. Manufacturing arrangements draw attention because so much value crosses the line: components in, finished goods out, and services and management charges alongside them. The two revenue authorities look at the same transactions from opposite sides, so a position documented for one has to survive being read by the other. The work is easier done while the arrangement is being built than reconstructed once a review has started.
I retired to Mexico — where is my pension taxed?
Settle residence first; everything else follows from it. Each country decides residence under its own rules, and where both claim you the treaty breaks the tie on facts rather than on paperwork. Only then does the question of which country may tax a particular pension arise, and that turns on what kind of arrangement it is. US citizens continue to file at home in any event, so for most retirees in this corridor the practical question is not whether to file but what belongs in each return and which country's tax the other relieves.
I sold my Mexican property — how is that reported at home?
Two computations, on two sets of rules, from one set of facts. Mexico taxes the disposal under its own rules and its own procedure; the United States requires the same disposal reported, with the gain computed under domestic rules from the acquisition history. Relief is then claimed for the Mexican tax actually borne. The difficult part is usually the cost side — purchase costs, improvements, and the currency the records are kept in — and where the property was held through a bank trust arrangement, the characterisation of that arrangement shapes how the disposal is reported.
What is a totalization agreement and how do I use one?
A social security agreement that stops you contributing to two systems for the same work, and lets periods in both count towards benefit eligibility in either. Which system you stay in depends on the agreement's rules for your situation — a seconded employee usually remains in the home system for a set period, a locally hired one usually joins the host system. You evidence it with a certificate of coverage obtained before or shortly after the assignment starts. See certificates of coverage.
I work remotely from another country for a company back home — who taxes me?
Usually the country you are physically in, because employment income is generally sourced where the work is done, with your residence country taxing it as well if you are resident there and giving credit. Three things follow: your employer may acquire withholding and social security obligations where you sit, a treaty tie-breaker may be needed if both countries call you resident, and a short trip that becomes a long stay can cross a residence threshold nobody was watching. See remote workers and digital nomads.
