Getting Married? A Simple Tax Guide for Your First Year Filing Together

At a Glance

Marriage brings meaningful personal change, but it also creates a new financial landscape—especially at tax time. Once you are married, the IRS and state tax agencies view you differently, and those changes can affect your withholding, credits, and total tax due. Understanding these shifts early can prevent surprises and position you for better tax outcomes.

Contents

1. Why Marriage Changes Your Taxes
2. Filing Status Options
3. Why Many Newly Married Couples Owe at Tax Time
4. State Taxes After Marriage
5. Name Changes and IRS Records
6. What to Keep in Mind for Your First Joint Return
7. Newlywed Tax Prep Checklist
8. Looking Ahead

Why Marriage Changes Your Taxes

While your day-to-day financial habits may not shift immediately after the wedding, the tax system adjusts your status right away. Federal tax law treats married couples as a single tax unit, which alters how income, deductions, and credits are calculated. Knowing these foundational rules helps set expectations for your first tax season as a married couple.

• You are considered married for the entire year – For federal income tax purposes, your marital status on December 31 determines your status for the entire calendar year. Even if you get married late in the year, your tax return will be filed as a married couple.
• The IRS now views you as one household – The tax system shifts from analyzing each partner’s income and deductions separately to treating you as a single economic unit. This change affects the way adjustments, credits, and deductions are calculated—sometimes increasing your tax liability, sometimes reducing it.
• Combined income affects tax brackets and credits –When incomes are combined, the total can push a couple into a higher marginal tax bracket, limit certain deductions, or phase out credits that were previously available. For example, two high-earning professionals in Maine may find that combining salaries results in reduced access to education credits or the Child and Dependent Care Credit once they have children.

Filing Status Options

Selecting the correct filing status is one of the first and most important decisions couples make at tax time. While most married couples file jointly, certain financial or legal considerations can make separate filing more appropriate. Understanding these differences helps you choose the structure that best fits your situation.

Married Filing Jointly vs. Married Filing Separately – Married couples must choose between two filing statuses:

1. Married Filing Jointly (MFJ) – both spouses report all income and deductions on one return.
2. Married Filing Separately (MFS) – each spouse files an individual return reporting only their own income and certain limited deductions.

Why most couples file jointly –Joint filing typically yields a lower combined tax liability and allows access to credits unavailable on separate returns. Tax benefits such as the Child Tax Credit, education credits, and certain itemized deductions are significantly limited when filing separately.

When filing separately may make sense – There are special circumstances where MFS can be beneficial, including:

• Large medical expenses where one spouse’s lower income allows for a greater deduction.
• Student loan repayment situations that depend on adjusted gross income.
• Concerns about liability or uncertainty regarding a spouse’s tax compliance.

These considerations usually apply similarly across states, though state-specific deductions may calculate differently.

Why Many Newly Married Couples Owe at Tax Time

It is common for couples to experience a balance due when filing jointly for the first time. This often results not from mistakes but from how withholding interacts with combined income. Understanding the most frequent causes can prevent surprises and better align your tax payments with your true liability.

• Higher combined income without added deductions – Two individuals may each have sufficient withholding based on their solo income, yet when combined they may enter a higher bracket. Because employers withhold based on the assumption of a single income, this shift often leaves couples under-withheld.
• Renters and couples without children often feel this the most – Without major deductions—such as mortgage interest or dependent credits—newly married renters may see their total tax bill increase compared to their single years.
• Under-withholding and outdated W-4 forms – Many couples postpone updating their W-4s. Old forms assume single filing status and do not coordinate income between spouses. This is a frequent reason taxpayers discover a balance due in April, especially when both partners earn moderate to high wages.

State Taxes After Marriage

State taxes often change alongside federal taxes, but not always in the same way. Understanding how your state treats married taxpayers—particularly if you and your spouse work in different states—is essential for accurate withholding and planning.

• State filing status generally follows federal –Most states require your state filing status to match your federal status. If you file jointly for federal purposes, you typically file jointly with the state as well.
• State tax rules differ from federal rules –Although filing status may align, taxable income calculations vary. Maine’s credit and deduction structure differs from states like Massachusetts, while New Hampshire’s limited income tax system creates entirely different cross-border considerations.
• Withholding and multi-state considerations – Couples working in different states must review withholding carefully. For instance, a Maine resident working in New Hampshire may owe Maine tax on all wages even if no Maine withholding is taken. Coordinated planning can avoid a year-end shortfall.

Name Changes and IRS Records

Administrative steps can shape how smoothly your first married filing experience goes. Name mismatches and outdated records often delay refunds or trigger correspondence from the IRS. A few timely updates can prevent avoidable complications.

• Update your name with Social Security – If you change your name after marriage, notify the Social Security Administration (SSA). The IRS uses SSA records to match names and Social Security numbers on tax returns, so updating your SSA records is sufficient. The IRS does not need a copy of your marriage certificate.
• IRS matching requirements –A mismatch between the return and SSA records can delay refunds or cause the return to be flagged for manual review. A year-end name change may not be processed before filing season, so timing matters.

What to Keep in Mind for Your First Joint Return

Your first year filing jointly is often more complex than expected, especially if you both earn significant income or have business or investment activity. Taking time to plan ahead allows you to understand your new tax profile and avoid last-minute surprises.

• Importance of planning ahead – Reviewing income, withholding, benefit elections, and investment activity early helps estimate your new tax position. Business owners and high-income households often benefit most from this step.
• Marriage alone does not create major tax savings – Tax savings generally come from new deductions or credits, not from the change in marital status itself. In fact, two high earners with similar incomes may see their liability rise.
• Many benefits come later with other life events – Tax advantages may expand as your household evolves—buying a home, having children, or starting a business can all introduce new planning opportunities.

Newlywed Tax Prep Checklist

Use this checklist to make your first year filing together as efficient as possible:

• Decide whether joint or separate filing makes the most sense for your situation.
• Update both federal and state W-4 forms after marriage.
• Update your name with the Social Security Administration if applicable.
• Review health insurance and employer benefit elections.
• Schedule a proactive tax planning meeting before your first joint return.

Looking Ahead

Marriage represents a new financial chapter as well as a personal milestone, and thoughtful tax planning helps you start that chapter on solid footing. A pre-filing discussion with a tax advisor can reveal opportunities, prevent unexpected liabilities, and align your tax strategy with your long-term financial goals.

Sahaley DuPree is a Senior Accountant at ARB specializing in tax compliance and planning for private client services, auto dealerships, and construction companies. Beyond her client work, she is actively involved in ARB’s recruiting and community committees, where she helps foster the firm’s culture and advance its outreach in the greater Portland community.