Ditto, butterfinger! I've been doing the same thing simply so I could e-file and keep it simple. I've been using the same logic as you! But this logic is flawed. If the instruction booklet says under Single that you "can" check the box if you
weren't married on the last day of that tax year, then the converse would also have to be true - that if you
were married, you
cannot check the "Single status" box. Likewise under Married, if it says you "can" check the box if you
were married at the end of the tax year, then again, the converse would have to be true - that if you
weren't married, you
cannot check the "Married status" box.
I know it's a lot easier to rationalize our way around it then to own up to what we actually need to do. Now, in my case, my filing status has no bearing on my tax liability so tax evasion is not a question but that is the one thing you do not want the IRS to think you're trying to do. When we submit our tax forms, we are in essence signing an affidavit stating that our selected filing status is true and correct.
Now, I haven't changed my surname since getting married and I don't intend to. But I think as soon as you do, that puts them (the IRS) on notice that your filing status has possibly changed. If your tax liability would change as a result of your using the correct filing status, then yes, I would think good and hard about amending your past years returns. I wouldn't think you'd have to amend them beyond the statute of limitations which I think is now three years for audits? That would have to be checked.
As I'm looking into the possibilities of getting a Green Card for my British hubby to stay with me in the States when I go back, I could be in trouble if I have to produce the past couple of years tax returns simply because I filed as Single - so if you think you would ever need to produce your tax returns for any official business, it's always best to have told the truth.
As long as you file as Married filing Separately (even though your spouse is technically not filing) then you don't have to account for his income, his assets or anything else of his. The income tax return, in that case is only about you. If you decide at some point to file as Married filing Jointly, then his income and assets become your "worldwide" income and assets and they have to be accounted for on the tax return, in essence combined with yours. Some couples prefer to file jointly as it can work out to have an advantage - paying less taxes. But that's not always the case. It can sometimes be fun to figure it out both ways before you actually file just to see if there is an advantage to you one way or the other.
About the NRA thing - there seems to be conflicting advice on this forum. If you're trying to fill in the 1040/1040A online, I highly suspect that it won't let you type "NRA" in the form field for SSN because that form field is specifically created for a numerical input. I hope somebody who has had some experience with this will correct me. However, I thought about trying to type Non Resident Alien or NRA in the field where the spouse's name is requested. And, I think somewhere on this forum someone suggested that you don't have to put anything at all.. don't even mention your spouse.
The advantage of filing your taxes online is that if you make a mistake or don't fill something in properly, the form is kicked back to you inside an hour and you have time to correct and submit it again, several times if you need to. If you are mailing your taxes by "snail-mail" and you've not filled in something correctly.. ie, maybe you decided to put "NRA" and they refused to accept it the way that you wrote it, you might not find out and have a chance to correct and resubmit it in time. That's worrisome.
But to reiterate: Yes, you and I should be filing as Married filing Separately -
not Single. I thought life would be less expensive and less complicated when I moved to the UK, but the very opposite has proved true. It's a bugger!