Getting married: what changes on your taxes

If you were married on the last day of the year, the return treats you as married for the whole year. That single rule drives almost everything else that changes.

Do the name change first

If either of you took a new surname, tell the Social Security Administration before you file anything. The name on a return is checked against Social Security's record, and a mismatch is one of the most ordinary reasons an electronically filed return comes back rejected. The change takes an application and proof of the change, and the Social Security Administration's number and card page sets out what to send and where. Start it early. Records take time to update, and April is the wrong month to find out that yours has not.

Married on the last day means married all year

Publication 501 puts the whole test on the last day of the tax year. A couple married and living together meets it. So does a couple living apart but not legally separated under a decree of divorce or separate maintenance, and a couple separated under an interlocutory decree of divorce that is not yet final. Nothing about the date of the wedding splits the year, and there is no proration for the months before it.

Joint or separate: how to decide

Filing jointly usually costs less tax, but usually is not always, and the only reliable test is to figure the return both ways before you choose. What tips the decision is the list of things a separate return gives up. The IRS names them: in most cases the credit for child and dependent care expenses; the earned income credit, which a separate return puts out of reach unless a qualifying child lives with you and the rest of a narrow set of conditions is met; the education credits and the deduction for student loan interest; and a capital loss deduction limit half the size of the one on a joint return. The tax rate on a separate return is generally higher as well.

One more rule catches couples out. If one spouse itemizes, the other cannot claim the standard deduction at all. That deduction is $31,500 on a joint return, against $15,750 on each separate one, so losing it outright is what turns this into a real decision rather than a technicality when only one of you has deductions worth itemizing.

When separate can still win

Three cases come up often enough to name. A large medical or casualty deduction measured against one spouse's smaller income can clear a floor it would never clear against the two incomes combined. A spouse who wants to keep responsibility for a return separate has a reason that is not about arithmetic at all. And a student loan repayment plan tied to one income can be worth more than the credits a separate return costs. Married filing separately for student loans in Texas works that last case through, and it turns on the numbers in front of you rather than on principle.

Redo both W-4s

This is the section that prevents a bill. Each employer withholds as though the job it pays for were the household's only income, so two salaries are each withheld at the rate a single salary would carry, and the shortfall only appears when the two land on one return. Step 2 of the W-4 exists for exactly this. Both of you hand in a new form; changing one of them is half a fix. Form W-4, line by line covers what each step asks for, and a withholding checkup for 2026 covers when to run the numbers again.

Texas: community property in one paragraph

Texas is a community property state, and that changes what a separate return in Texas looks like. Income either of you earns during the marriage is generally community income and is split between you if you file separately, and in Texas income from most separate property is community income too. So a separate return here is not simply your W-2 on your return and your spouse's on theirs. The split has to be worked out and reported on both returns, which is why separate filing in Texas usually needs a preparer rather than an evening with software.

The small list of things to update

Names with the Social Security Administration, for whichever of you changed one. Your address with the IRS, if the marriage came with a move. A new W-4 at each job. The bank details you file with, if the refund is going to a joint account. And the beneficiary forms on retirement accounts and insurance policies, which are not tax at all but get forgotten in the same week as everything else. Filing status sets out the five statuses and what each one carries, once the decision in front of you is which of the two married ones to use.