U.S. passport, Toronto mortgage? Lucky you: two tax seasons, every spring, for as long as you hold that passport. Canada wants a return because you’re resident here, and it taxes your income from anywhere in the world. The U.S. wants…

Tax law doesn’t hold still. Rules shift, thresholds get adjusted, credits get introduced or phased out, and provisions that were relevant last year sometimes become irrelevant this year, replaced by something new that most people haven’t even heard about yet.…