KEY POINTS
  • The so-called "marriage penalty" kicks in when tax-bracket thresholds, deductions and credits are not double the amount allowed for single filers.
  • If you were married at any point last year, you're required to file your 2020 tax return as a married couple.
  • The deadline this year for filing your federal tax return is May 17.

Some newlyweds get an unwelcome gift from the IRS: a bigger tax bill. 

While many couples end up paying less in taxes after tying the knot, some face a "marriage penalty" — that is, they end up paying more in taxes than if they had remained unmarried and filed as single taxpayers.