Karen - forget efiling; think just filing. It's my understanding that one can only file for ten years. So, assuming you are looking at a 2023 year-end, you can only file for 2014 - 2023 inclusive.
HOWEVER. My advice is that you begin with the 2010 year-end and enter all the data in Profile if it lets you. Actually, if you can, I would suggest you enter the 2009 information from whatever you can get and then just keep carrying forward from there to the present, filling out each year as best you can. Even if you are not allowed to either efile or file all these returns, at least you have now produced a decent record of what should have been filed. This is important because CRA can go back more than ten years if they have a reason; not filing for over a dozen years is probably a legitimate reason.
Hope this helps.
Jo
