Does one engineer on a site create a permanent establishment for the employer?
The construction permanent-establishment provision in most treaties does not look at the individual. It looks at the site or the project, and asks how long that project lasted. So the relevant question is not how many days you personally spent abroad, but when work on the site began, when it finished, and whether your employer's involvement spanned that period. An engineer who flies in and out of a long-running project can therefore be working inside a permanent establishment created by the project itself. Ask for the contract dates and the site mobilisation records before drawing any conclusion about your own position.
Our site project overran the treaty threshold and nobody registered locally — what now?
Then the exposure is the employer's before it is yours. Once the project passes the duration set in the treaty, the host country can tax the profit attributable to that site, and the obligation dates from the point the threshold was crossed rather than from the day somebody notices. The work is usually the same, in this order: establish the site's real start and finish from mobilisation and handover records, register, file for the periods still open, and compute the profit attributable to the site rather than to the company as a whole. Late registration handled deliberately reads very differently to a host authority than one found in an audit.
Why does my employer withhold only at home when I work abroad?
Because home-country payroll runs on the employment contract, and nothing in that contract tells the payroll team where you stood last Tuesday. Where a site creates a permanent establishment, the host country generally expects payroll there for the employment exercised at that site, and the treaty relief your employer is assuming may not survive once the establishment exists. The result is tax paid in the wrong place: correct in form, wrong in substance, and put right only by a host-country filing and a credit claim at home. Raise it with the employer, because the fix belongs on their payroll rather than on your return.
Do design hours at the home office count towards the project duration?
They are a separate question from site presence. The construction provision counts the life of the site or installation project, so work physically performed at the site — supervision, inspection, commissioning of structures — feeds the duration test most directly. Design and drafting carried out in your own country is ordinarily taxed where it is performed, and the treaty article that governs it may not be the construction one at all. Where a single contract covers both, the sensible step is to split the fee by what was done where, and to keep the timesheets and drawing registers that support the split.
Is my site allowance taxable in the country where the site is?
Each element of an assignment package has to be looked at on its own. Accommodation, travel to and from site, meals, hardship uplifts and relocation costs are treated differently from each other, and differently again by the host country and the home country. That is why two engineers on the same project can hold payslips that do not match: their packages differ, and so does the treatment. The useful exercise is to list every line of the package, decide the treatment of each under host-country rules and under the treaty, then reconcile that against what payroll actually did.
Does the duration clock reset if we leave the site and come back?
Usually not. A temporary interruption — a seasonal shutdown, a materials delay, a dispute that stops work for a while — is generally treated as part of the same project rather than as the end of one and the start of another. That matters because a project can look short when counted in working days and long when counted in elapsed time. Where the point is likely to be argued, build the chronology early from site diaries, mobilisation and demobilisation records and handover certificates, so the position rests on documents rather than on recollection.
Is the sale of foreign property taxable where I live?
For a resident, yes — worldwide gains are taxable, and the gain is computed in your own currency, so the exchange rate at purchase and at sale changes the number even when the local-currency price did not move. The country where the property sits usually taxes it too, often with a withholding or clearance step before closing, and that tax becomes a credit. A principal residence relief may apply to a home abroad on the same terms as one at home. See principal residence and foreign property.
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.
