What Changes on Your Tax Return the Year You Get Married?
A wedding changes plenty about daily life, and it also resets a fairly specific rule on the next tax return, one that surprises some newly married couples: the calendar, not the honeymoon, decides how the whole year gets filed.
The short answer
Marital status is determined as of December 31 of the tax year, so getting married any time during the year, even on New Year’s Eve, generally means filing as married for that entire year rather than filing separately for the months before the wedding. From there, the couple generally chooses between filing jointly or filing separately, and it’s worth updating withholding to reflect the new household income.
Why the December 31 rule matters
Because the government looks only at status on the last day of the year, there’s no partial-year “single” filing available for months spent unmarried before a wedding that happened in, say, October. This can feel counterintuitive, but it also means the timing of a wedding within a given calendar year doesn’t change which filing status applies once the year ends — a couple married in January and a couple married in December both file as married for that full year.
Choosing between joint and separate filing
Married couples generally choose between two filing statuses each year: filing a joint return that combines both spouses’ income, deductions, and credits, or filing separately, which keeps each spouse’s return distinct. Filing jointly is the more common choice and often results in a lower combined tax bill, though the outcome depends on each spouse’s income and isn’t the same in every situation. Filing separately can make sense in specific circumstances, such as wanting to keep tax liability clearly separated, but it also means giving up eligibility for some credits and deductions available to joint filers. Reviewing both options, sometimes by preparing the numbers each way, is generally the more careful approach.
Standard deduction and other adjustments
Filing status also changes which standard deduction applies, since married filers, whether filing jointly or separately, use different standard amounts than single or head of household filers. A newly married couple with two incomes may also find their combined income shifts which portions are taxed at which rates, since brackets and deduction amounts differ by filing status rather than applying uniformly.
Updating withholding after the wedding
Each spouse’s paycheck withholding was likely set up using a Form W-4 filed back when they were single, which doesn’t account for a spouse’s income or a shared household. Combined income from two working spouses can sometimes push a couple into under-withholding if neither W-4 was updated to reflect the marriage, so reviewing and resubmitting a W-4 with the new household situation in mind is a practical step to take soon after the wedding rather than waiting until the next filing season.
A practical habit
Because the year-end marital status rule applies retroactively to the whole year, it’s worth treating a wedding, whenever it happens during the year, as a trigger to review filing status options and update withholding right away rather than assuming nothing changes until the following January.