The surviving spouse must be the first taxpayer on the return as that social security number is what IRS uses. if the deceased spouse is listed first, the return will reject immediately. If you already finished the return and it rejected, changing the names around is not as simple as it seems. You will need to go through each form on the return as changing the names, changes the names on W-2s, K-1s, 1099s etc. -- even though you did not want those forms to change. In the end, it works well and 1040 was accepted quickly.
