Why does changing who's W-2 change tax due

[zmildon]

I accidentally added a W-2 and said it was mine. When I switched it to being my wife's, our tax due went up thousands. Why?

[Opus 17]

The social security limit is around $118,000 per year per taxpayer (more or less, I didn't look it up.)  If you and your wife make close to that amount, then assigning both W-2s to the same person makes it look like one person had too much social security withheld, and a social security refund is added to your tax refund.  When you correctly assign the W-2s, the program does not compute a SS refund because you didn't overpay.  (If you assign the W-2s wrong and get the SS refund in error, you WILL get a letter and a bill.)