I am sorry to hear that you are having this problem. If you are on the page asking for your husband’s SIN number, scroll down to the bottom and look for a grey “Back” button. Click on that and it will take you back to the page where it asks you for your own information. There you can double check what you have put for your own SIN number. If you accidentally put his number as your own, you can fix it, and then click on the blue “Continue” button at the bottom of the page to go forward to your husband’s information page.
I am getting the same error message over and over again and although sure I did not accidentally put my spouse's in my space I did press back to double check and as I expected I had not entered his information. I have filled in the page about 8 different times now and can also assure you I am not now entering my sin on that line so they match. I am entering his sin which is different from my own. How do I make the error go away now. I can also assure you I am entering it correctly 9 digits no spaces when I finish and move on the spaces are added for me. I've also tried adding the spaces myself but it doesn't appear to matter how I type it, the program thinks they match.