Tax filing mistakes are fairly common. Still, you don’t want to make a preventable mistake if you can help it.
From delayed refunds and rejected returns to the potential for penalties, tax mistakes can come back to bite you. Learn why it’s important to get your taxes right the first time, plus the most common tax mistakes to avoid.
Why Tax Filing Mistakes Can Be a Big Deal
Filing taxes incorrectly isn’t the end of the world, but it’s not good, either. While the IRS will sometimes automatically correct small math issues, mistakes can also delay processing or require more hassle and paperwork.
For example:
- A typo in your bank account number might delay your refund.
- A wrong Social Security number may cause your return to be rejected.
- Missing income could trigger a follow-up notice.
- Filing late may result in late-filing penalties.
These are just some of the reasons why it’s so important to review your return before you submit it.
10 Common Tax Filing Mistakes and How To Avoid Them
Some tax filing mistakes are more of a headache than others. Below are some of the top ten most common mistakes, plus how to avoid them.
1. Filing Before You Have All Your Tax Forms
We get it: you’re eager to submit your taxes and get it over with. But your W-2 income form might arrive within a few weeks, while a 1099 for a side job shows up at the end of February. Whatever the reason, missing forms can create mismatches, and the IRS doesn’t like inconsistencies.
To avoid this, it’s best to wait to file until all your forms have arrived.
2. Entering Names, Social Security Numbers, or Bank Details Incorrectly
This is one of the most common tax return mistakes, especially if you’re entering the information in a hurry. Something as simple as a dependent’s name not matching their Social Security number can create huge problems. And mistyping your bank account number can delay your refund.
As with most tax filing mistakes, the best way to avoid this issue is to slow down and double-check your details before filing taxes.
3. Choosing the Wrong Filing Status
Your filing status is the category the IRS uses to determine tax rules for your situation. The options here are:
- Single
- Married filing jointly
- Married filing separately
- Head of household
Your filing status affects eligibility for certain tax deductions and credits, and can affect how much tax you owe. If you aren’t sure which option to pick, check out the IRS’s guidelines or ask a tax professional for help.
4. Making Math Mistakes or Manual Entry Errors
Transposing numbers or mixing up decimals are small mistakes that have a big impact. While it’s good to know how to file taxes yourself, tax filing software can virtually eliminate this tax return error. It automatically does the math and flags any inconsistencies. Of course, you should still review everything before submitting, but automating more of the process can help you avoid errors.
5. Leaving Out Income From Side Work or Part-Time Jobs
You might think a small amount of money “doesn’t count,” but generally, you should still report all taxable income. If you don’t declare it, it creates a mismatch between what the IRS sees and what you report.
Review all income sources before filing, including:
- Gig work
- Freelance jobs
- Contract work
- Part-time employment
- Online selling income
Even small amounts matter. As of 2026, the minimum threshold increased from $600 to $2,000, but it’s better to be safe than sorry.
6. Missing Tax Deductions and Credits
If you overlook opportunities to save, you’re leaving money on the table. Deductions lower your taxable income, while credits directly reduce how much you owe.
For example, some people qualify for programs like the Earned Income Tax Credit, which is a tax benefit for certain lower-income workers. Others may benefit from contributions to eligible retirement accounts, depending on the type of account and their situation.
7. Claiming Credits or Deductions You Don’t Qualify For
On the flipside, you should never assume that you’re eligible for credits or deductions without double-checking. For example, some credits have rules tied to income, residency, or filing status. Read the requirements carefully or ask a tax professional for advice if you’re unsure.
8. Not Reviewing Tax Withholding During the Year
Tax withholding is the amount of tax taken out of your paycheck throughout the year. Withholding too little could leave you with a hefty tax bill due all at once. But if you withhold too much, you could miss out on that income throughout the year.
Review your withholdings periodically, especially at the start of the year, but also after:
- Starting a new job
- Marriage
- Divorce
- Income changes or big life changes
9. Filing Late or Missing the Deadline to Pay
Did tax season deadlines whoosh past you? It happens.
Still, you can expect to pay late filing penalties if you miss the filing deadline. It’s also important to know that filing late and paying late are different things. You can still file on time even if you can’t pay your full tax bill immediately.
So, even if you can’t pay right now, the IRS would much rather you go ahead and file, or request an extension, instead of just ignoring them.
If you’re forgetful, set reminders on your phone or calendar well in advance of Tax Day so you don’t overlook filing your return or asking for an extension.
10. Skipping Help When Your Return Is More Complicated
If you have a complicated tax situation, now’s not the time to DIY your taxes. A lot of things increase the chance of filing taxes incorrectly, like:
- Big life changes
- Multiple income sources
- Freelancing
- New tax credits
- Owning a business
Some tax software can handle this for you, but a qualified tax professional is also helpful.
A Final Review Can Save You Stress Later
Most tax filing mistakes are preventable with a careful final review before you submit. Taking a few extra minutes to slow down, check your entries, and confirm key details can help you catch common errors early.
And if you do spot a mistake after filing, it’s not the end of the world. The important thing is correcting it as soon as possible. Acting quickly can help reduce delays, limit stress, and avoid potential penalties.
