Three countries want to tax me — which treaty applies?
All of the relevant ones, and none of them on its own. Treaties are bilateral: each operates between its own pair of countries, so with three in play there is no single agreement that resolves your position. There are two or three agreements applied in sequence. The order is what makes it workable. Residence is settled first, because most treaty articles depend on it, and only then is each stream of income traced from where it arises to where you are resident. Skip the first step and the rest of the analysis has nothing to stand on.
Can I use a treaty between two countries I do not live in?
Generally not in your own right. A treaty allocates taxing rights between its two parties and is available to residents of those parties, so a treaty between the country where income arises and a third country does nothing for you if you are resident in neither. This is the point where triangular positions go wrong: a payer applies a reduced rate under a treaty that does not cover the recipient, and the shortfall surfaces later. Check which pair of countries each claim is actually made between before any rate is applied.
Which country do I settle my residence with first?
Residence is settled pair by pair, not once for the whole arrangement, and you start with the pair where both countries are genuinely claiming you as a resident under their own law. That is the conflict a treaty can resolve. A third country taxing you only because income arises there is not competing for your residence, so it does not belong in that first step — it comes in at the sourcing stage. Establish the residence answer in writing before touching the income analysis, because every stream after that depends on it.
What if two treaties give different answers on the same income?
They can, and it is one of the genuine hazards of a three-country position: applied in sequence, two bilateral agreements can point in different directions on the same receipt, leaving tax charged twice with no complete credit. There is no third treaty that overrides them. The mechanism is the competent-authority route, where the administrations involved resolve the position between themselves. It is a formal application built on the facts and the sequence already documented, so the analysis done at the filing stage is what the application rests on.
Is there one treaty that covers all three countries at once?
No. Bilateral is not an incidental feature of these agreements, it is how they work, so nothing in the network resolves three countries in a single instrument. What you do instead is identify each pair that matters, apply the relevant agreement within that pair, and record the order you did it in. The output is a memorandum showing residence settled first, then each income stream traced from source to residence, with the point where any conflict arises identified rather than glossed over.
My employer, home and clients are in three countries — where do I file?
Probably in more than one, and the filing question comes after the analysis rather than before it. Each country's obligation arises under its own law and is not removed by a treaty; the treaty affects what is taxable and what relief is due, which is a matter for the return. So the order of work is residence first, then each stream of income traced from where it arises to where you are resident, then the filings that follow. Returns prepared in that order tell all three administrations a consistent story.
Which country taxes my government pension or social security?
The treaty decides, and the answer differs by the type of retirement income. Many treaties give social security to the country of residence, sometimes exclusively, while a pension for government service can stay taxable only in the paying country. Some treaties also cap the taxable proportion or preserve an exemption the source country gives its own residents. Because the categories are distinct, one household can have two pensions taxed by two different countries. See the pensions and annuities article.
How does an NRI prove residence to get the treaty rate?
With a tax residency certificate issued by the country you are resident in, plus Form 10F giving the details the certificate does not carry, plus a PAN in the payer's records. The certificate has to cover the period of the payment, and the payer needs it before paying, not afterwards. Missing any of the three and the deductor is obliged to withhold at the domestic rate, which turns a rate reduction into a refund claim. See TRC against Form 10F.
