How do I know if my cross-border return was done properly?
You check the three things that go wrong most often rather than re-keying the whole return. A second opinion on a filed cross-border return finds much the same pattern most of the time: a foreign credit that was available and not claimed, an information return the facts required and nobody filed, and a treaty position taken without the disclosure that goes with it. Each of those is checkable against documents you already hold. What a review cannot do is tell you the return is right by reading it alone — the test is whether the return follows from the facts, so the facts are where the work starts.
What does a second opinion on a tax return actually check?
Three things, in order. It re-derives the residency conclusion from the facts rather than adopting the one the return assumed, because almost everything else depends on it. It recomputes the foreign credits by category and by country, which is where amounts claimed as a single figure tend to fall apart. And it lists the information returns the facts required, then compares that list with what was actually filed. Where something is wrong, the review stops at identifying it and quantifying it; whether to amend or to use a disclosure route is the next decision, and it is taken separately.
My accountant missed a foreign tax credit, can I still claim it?
Often, and that is the commonest single finding in this kind of review. Whether the claim is still available turns on the limitation period for the year in the country where the credit belongs, so the first step is to establish which years are still open rather than to prepare a claim you cannot file. The second is to recompute the credit by category and by country, since a credit is not one pooled number and the figure originally claimed is frequently right in total and wrong in composition. A claim built on the correct categorisation survives review; one that simply asks for more does not.
What if the review finds a form I never filed?
Then you have a decision to make, and you make it knowing the position rather than discovering it later. A missed information return is not the same problem as unpaid tax — the exposure usually attaches to the form, and tax may not be owed at all. Two routes exist: amend and file what was missing, or use a disclosure route that deals with the omission and the years behind it together. Which one fits depends on how many years are involved, why the form was missed, and what is still open. The sequence of filings matters here more than the arithmetic does.
Does a second opinion mean I will have to amend the return?
No. A review establishes the position; amending is a separate decision taken afterwards, with the alternatives on the table. A review often ends with a note explaining why a difference found is not worth disturbing the year for, or why the year is closed anyway. Where an amendment is warranted, the next question is whether to amend or to disclose, and that depends on what was missed and how far back it goes. Treating the review and the remedy as one step is what leads to a return being amended before anyone has worked out whether amending is the right vehicle.
Can a second review make things worse by finding problems?
It changes what you know, not what is true. The exposure attached to an unfiled information return exists whether or not anyone has looked, and it generally grows with the number of years, so finding it earlier widens the choice of routes rather than narrowing it. What a review does close off is the comfortable position of not having asked. That is a real consideration, and it is worth raising before the work starts rather than after. In practice the findings are usually a mixture: something that costs, and a credit or a position that recovers part of it.
What is double tax relief and how is it given?
Three mechanisms, and which one you get depends on your residence country's law and the treaty. Exemption leaves the foreign income out of the residence-country base. Credit taxes it and then subtracts the foreign tax, capped at the residence-country tax on that income. Deduction merely reduces taxable income by the foreign tax, and is usually the weakest. Canada and the United States lead with credit; several treaties give exemption for specific income types. See claiming the credit.
Is double taxation legal?
Yes. Nothing prevents two countries from taxing the same income under their own domestic law — each is exercising its own jurisdiction. What treaties and credit systems do is relieve the outcome rather than prohibit the charge, and relief is generally something you must claim on a return or a form, not something applied automatically. Miss the claim and the double charge stands. Double taxation explains the mechanism.
