Does the treaty exempt me if my train crosses the border?
Only if every condition in the employment article is met at once. Rail crew normally sit inside the ordinary employment article, which can relieve the host country's share of the pay where your presence there stays inside the permitted limit, your employer is not resident in that country, and the cost of your employment is not borne by a permanent establishment there. Those tests apply together. Meeting some of them is not partial exemption, it is no exemption, and the host country can then tax the days worked on its side. Because the article carries no transport-specific shortcut, the answer depends on facts about your employer as much as on your own roster.
Do I still file abroad if my employer withholds only at home?
Often yes, because withholding and liability are separate questions. A railway employer registered in one country withholds there, since its payroll system and its legal duty sit there, and that says nothing about whether the days you worked on the other side of the border are taxable in that other country. If the employment article's conditions are satisfied there may be no host liability and no filing. If they are not, there is a liability with nothing withheld against it, and the host return is how it gets settled. The first step is to test the conditions in writing rather than read the payslip as a conclusion.
Why will nobody confirm my treaty exemption in writing?
Because most of the facts the exemption turns on belong to your employer, not to you. Whether the employer is resident in the host country, whether an establishment there bears the cost of your employment, and how your presence is counted are matters for the employer's records and its own tax position. A payroll clerk will not certify them, and a tax authority will generally not rule in advance without a formal request. What can be done is to set out the conditions, obtain the employer's confirmation of the facts it controls, and keep the analysis on file. The exemption is then claimed on the return and supported from that file if it is questioned.
Can I stop paying social security in both countries at once?
Possibly, and the instrument that decides it is usually a social security agreement rather than the tax treaty. Those agreements assign coverage to one system for a given period of work, and provide a certificate of coverage that relieves the contributions in the other. They are separate from the income tax analysis, so a person can be taxed in one country and covered in another. Where contributions have gone to both systems for years, the questions are which system had the right to them, whether a refund is available for the open periods, and whether the years already paid still count towards a benefit. Settle coverage going forward first, then look back.
How are my days counted if I finish a shift abroad?
Day counting is the mechanical part of the employment article and it is rarely done the same way in two treaties. Some count days of physical presence, including part-days, arrival and departure. Some count days worked. A crew member who begins a shift on one side of the border and ends it on the other can therefore be present in both countries on the same calendar day. What follows is practical. The roster, the run sheets and the relief arrangements are the evidence, and they have to be kept in the form the count requires. Establish which count applies before the year starts, because it decides which records matter.
Do transit operators crossing a city border face the same rules?
The framework is the same and the facts usually make it simpler. There is no special article for rail or bus crew, so the ordinary employment rules apply whether the run is international freight or a scheduled service that crosses a boundary and returns within a shift. What changes is presence. A crew member whose day always ends at the home depot accumulates far less presence abroad than one who rests across the border, and the employer's own footprint on the other side is often nothing at all. That combination makes the exemption conditions more likely to be satisfied, but they still have to be tested rather than assumed.
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 have not filed for several years while living abroad — what are my options?
Both countries have routes back, and using one before they contact you is what preserves the relief. On the US side there are procedures aimed at taxpayers whose failure was not wilful, including one designed for people living outside the country, and separate procedures for late account reports and information returns alone. Canada has its voluntary disclosures programme and taxpayer relief for penalties and interest. Filing quietly and hoping is the one approach with no protection attached to it. See catch-up filing.
