What determines the size of your tax refund

Your refund is the difference between what you paid in taxes during the year and what you actually owed. A larger refund does not mean you did well financially—it means you overpaid. The IRS held your money interest-free for months, and now you are getting it back. To increase your refund, you need to either reduce the taxes you owe or increase the taxes you already paid in.

Most people cannot change what they paid in without adjusting their paycheck withholding, which takes planning ahead. What you can do now is make sure you are claiming every deduction and credit you are may have access to to, and that you are reporting your income correctly. Missing deductions costs real money.

Key Takeaways

  • Your refund grows when you claim deductions you missed or when you may have access to for tax credits you did not know about—both reduce what you owe.
  • The Earned Income Tax Credit and Child Tax Credit are the two largest credits for most households and require specific income and family situations.
  • Common missed deductions include student loan interest, educator expenses, and charitable donations if you itemize instead of taking the standard deduction.
  • Changing your W-4 withholding now affects next year's refund, not this year's, so it only helps if you plan ahead.
  • A tax professional or free tax software can spot deductions and credits you might miss on your own.

Tax credits that directly reduce what you owe

A tax credit is worth more than a deduction because it reduces your tax bill dollar-for-dollar, not just your taxable income. If you owe $2,000 and you have a $1,000 credit, you now owe $1,000. If you have a $1,000 deduction, you reduce your taxable income by $1,000, which saves you roughly $120 to $370 depending on your tax bracket.

The Earned Income Tax Credit (EITC) is the largest credit for working people with low to moderate income. In 2024, it ranged from $600 to $3,995 depending on your income, filing status, and whether you have children. You do not have to have children to claim it, but the amount is much smaller without them. The IRS has a tool on its website to see if you may have access to.

The Child Tax Credit is $2,000 per child under 17 if your income is below certain thresholds. Part of it may be refundable, meaning you can get money back even if you owe no tax. The Additional Child Tax Credit can return up to $1,700 per child.

Other credits worth checking: the American Opportunity Tax Credit for education expenses (up to $2,500 per student), the Lifetime Learning Credit (up to $2,000), and the Saver's Credit if you contributed to a retirement account on a low income.

Deductions that lower your taxable income

You choose between the standard deduction and itemized deductions. The standard deduction for 2024 was $14,600 for single filers and $29,200 for married filing jointly. If your itemized deductions add up to more than that, itemizing saves you money. If not, take the standard deduction.

Common deductions people miss: student loan interest (up to $2,500 per year), educator expenses if you teach (up to $300), self-employed health insurance premiums, and contributions to a traditional IRA. If you itemize, you can deduct mortgage interest, property taxes (up to $10,000), charitable donations, and medical expenses above 7.5% of your income.

Charitable donations are only worth itemizing if you have enough other deductions to exceed the standard deduction. Many people give to charity but never see the tax benefit because they do not itemize. If you donate regularly, keeping receipts and tracking the amounts matters only if you plan to itemize.

Income you may have forgotten to report

The IRS knows about most of your income because employers and financial institutions report it. But some income does not get reported to the IRS automatically, and you have to catch it yourself. Forgetting to report it means you underpaid taxes, which shrinks your refund or turns it into a bill.

Income to check for: interest from savings accounts or CDs, dividends from investments, capital gains if you sold stocks or crypto, rental income, self-employment income from side work, and gambling winnings. If you received a 1099 form from anyone, that income needs to be on your return. If you did not receive a 1099 but earned money—say, cash tips or freelance work—you still have to report it.

Underreporting income is one of the most common audit triggers. The IRS matches what you report to the 1099s they receive. If the numbers do not match, they will contact you.

How withholding affects next year's refund

Your refund this year is locked in by what you already paid. Changing your withholding now only affects paychecks going forward. If you got a large refund this year, you overpaid throughout 2024. To get more money in your paycheck next year instead of waiting for a refund, you would adjust your W-4 with your employer before the end of 2024.

The opposite is also true: if you owed money this year, you underpaid. Adjusting your W-4 to withhold more means smaller paychecks but no bill next April. The IRS W-4 calculator on its website walks you through the math based on your situation.

This only matters if you want to change your cash flow. A refund is not better or worse than getting the money in your paycheck—it is just a matter of timing and preference.

Using tax software or a professional to find what you missed

Free tax software from the IRS Free File program or from companies like IRS Free File partners walks you through deductions and credits based on your answers. These tools ask questions designed to catch things you might miss. They cost nothing if your income is below certain thresholds (usually around $79,000 for 2024).

A tax professional—either a CPA, enrolled agent, or tax preparer—charges a fee but can spot deductions and credits specific to your situation. If you have self-employment income, rental property, investments, or a complex family situation, paying for help often returns more than it costs. Many preparers offer a free initial consultation.

The tradeoff: software is cheaper and faster if your situation is straightforward. A professional is worth it if you have income sources or life changes that create deductions or credits you would not think to look for.

Common mistakes that shrink your refund

Filing as single when you could file as head of household costs money. Head of household has a lower tax rate and higher standard deduction if you pay more than half the household expenses and have a dependent living with you. Many single parents miss this.

Claiming the wrong filing status for a spouse—married filing separately instead of married filing jointly—almost always results in a smaller refund. Married filing separately is rarely the best choice unless you have a specific reason, like protecting yourself from a spouse's tax debt.

Not claiming a dependent you are may have access to to claim, or claiming someone who does not meet the IRS rules, creates problems. A dependent must be a U.S. citizen, national, or resident alien; live with you for more than half the year; and be related to you or meet other specific tests. If you claim someone who does not may have access to, the IRS will disallow it and reduce your refund.

Rounding numbers instead of using exact amounts from your records can trigger an audit if the IRS thinks you are estimating. Use actual numbers from receipts, 1099s, and bank statements.

Frequently Asked Questions

Can I get a bigger refund by filing married filing separately?

No. Married filing separately almost always results in a smaller refund and higher taxes overall. You lose access to many credits and deductions. File jointly unless you have a specific reason, like protecting yourself from a spouse's tax debt or unpaid child support.

What if I missed a deduction last year?

You can file an amended return using Form 1040-X within three years of the original filing date. The IRS will recalculate your taxes and send you a refund if you overpaid. Many people find missed deductions years later and successfully recover the money.

Does paying estimated taxes increase my refund?

No. Estimated taxes are payments toward what you owe, just like withholding from a paycheck. They reduce what you owe at tax time, which may result in a refund if you overpaid, but they do not increase the refund itself. The refund is still the difference between what you paid and what you owed.

Should I claim my adult child as a dependent?

Only if they meet the IRS rules: they must be under 24 (or any age if disabled), a full-time student, live with you for more than half the year, and you provide more than half their financial support. If they earned more than $4,700 in 2024, they cannot be claimed as a dependent. If they claim themselves, you cannot claim them.

What if I have both W-2 income and self-employment income?

Report both on your return. Self-employment income goes on Schedule C, and you pay self-employment tax on it (Social Security and Medicare). You may also be able to deduct half of your self-employment tax and business expenses. A tax professional can help you structure this to minimize what you owe.