1040 full vs. dual

[elk]

I've gone back and read the posts starting from Dec, 2010, and I've had lots of my questions answered. nelsona, I must say you are saint for dealing with all our questions.

I have two more lingering questions that I couldn't find answers for, after which I think I'll be good to go.

1. I'm filing a departure return in Canada. In the income section of TurboTax, there is a box that says "Foreign". I'm assuming that I do *not* click it, since I'm only claiming Cnd income. Correct?

2. If I receive a refund in Canada, is there any advantage of filing a full 1040 over a dual? Am I right in that I'll be taxed like a US citizen for the resident portion of the year? If so, can I still claim moving expenses? (I learned from an earlier post that I can't claim them in Can.)

So, supposing I do file a dual 1040...

3. When is my official start date for US residency? The date my TN visa was issued? The day it became valid for work? Or the day I actually moved? I moved to MI June 8 with U-Haul, cat, etc. - started work June 15. However, I was in the U.S. for a week in April for a conference, and for another week in May to find an apartment and open a bank account. It was on this trip that I received the TN. To me, it it makes sense to use the June 8 date as the move-in date because that's when I permanently changed residence. But then there's the 10-day rule on the IRA site. If I use that example, then my residency would have begun around May 10 - not June.
I read in an earlier post that U.S. residency starts as soon as you get your TN - I wasn't sure if that referred to the date of issue, date of being valid, and if either of these dates overrides the 10-day rule.

You're expert guidance here would be very much appreciated. And I hope experiencing good karma for all the help you're giving people....

Thanks so much.

[nelsona]

I know of no situation when dual 1040NR/1040 is better than full 1040.

1040NR is simpler, but can only be used if one has not met SPT, and shoudl only be used if one's Cdn non- residency is clear and unambiguous. Once you need to file 1040 because of SPT, you maight as well file full year.

Remember that how you CHOOSE to file in US has NO IMPACT on how you MUST file in canada, with a factual departure date.

Your daperture date is not something you can really choose. You either left on this date or you didn't.