Canada (and I suspect many other G8 countries) does everything it can to tax those who leave to work overseas, whether you are a citizen or a landed immigrant. The Canada Revenue Agency (CRA) website has information about determining residency status, though it helps to have some tax knowledge to navigate to the documents you need. The website is:

www.cra-arc.gc.ca

Along the left you will see a link for 'A to Z Index.' Click there and look up residency for individuals. You should then find your way to documents called IT221 and NR73.

Residency is a question of fact, meaning that it depends upon your specific circumstances. This means that there is no objective test to determine residency; in fact, determining residency can be very subjective. Making it more problematic is the fact that Canada does not have a tax treaty with Qatar.

This means that when you determine your residency you should consult professional advice. In Canada, any of the National Chartered Accounting firms (such as Ernst and Young or Price Waterhouse Coopers) should be able to help you. A professional advisor can tell you how CRA might rule on your residency and, more importantly, how to change your circumstances (while complying with the law) to support a claim of non-residency.

Don't rely on advice you receive in a forum like this one - its worth spending a little $$ to consult professional advice and protect that $50k per year you might otherwise pay in tax.

You might also consider consulting a tax lawyer (as opposed to a Chartered Accountant) as conversations with lawyers are protected by privilege. (I.e.: CRA can force a accountant to reveal the name of a client, but cannot do the same to a lawyer).

In determining residency, CRA will look first to your primary residential ties, specifically:
- do you own a house in Canada?
- is you spouse (married or common law) still in Canada?
- do you have children still in Canada?

If you have a house and family in Canada it is likely that CRA would deem you to be a resident. But there are always mitigating factors. For example, it may not be wise (or even possible) to sell a house in Canada now. (For example, if your house is worth less than the mortgage value, there is little point in selling.) So CRA will not 'automatically' deem you a resident just because you own a house in Canada.

There are also secondary, less important considerations in determining residency. For example, CRA regards the following as indicators of residency:
- provincial medical insurance overage
- social ties in Canada (e.g.: church membership)
- personal property in Canada (e.g.: stored furniture)
- Canadian drivers licence
- a 'seasonal dwelling' (e.g.: cottage)
- a vehicle owned in Canada
- Canadian bank accounts, RRSP's, credit cards

As you can see, the list is quite comprehensive and, I believe, is designed to deem someone to be resident when in fact they are not. I hope your professional advisor can recommend the things you need to do to convince CRA that you are indeed a non-resident.

So seek advice before determining your residency status so you can ensure that you are not breaking any laws. Good luck.