7 Common Tax Filing Mistakes and How to Avoid Them

April is just around the corner, which means — you guessed it — it’s tax time. 

Whether you expect a hefty refund or anticipate having to shell out a few extra dollars, you can make the most of the upcoming tax season by steering clear of potential bumps in the road.

Here are seven common mistakes and a few tips on how you can avoid them. Remember to consult your licensed tax professional for the most up-to-date information on taxes and federal and state tax laws.

1. Missing the Deadline

Showing up late can be fashionable for parties, but it isn’t necessarily the best etiquette when filing your income tax returns.

The consequences for missing the April tax-filing deadline for federal returns vary depending on whether you owe money or are in line for a refund. Case in point: You can file your return up to three years from the due date if you’re fortunate enough to be getting money back from the Internal Revenue Service (IRS).

If you’re filing quarterly taxes, on the other hand, you’ll have not one, but four deadlines to keep in mind.

On the other hand, if you’re slated to pony up more cash and you don’t file your tax returns on time, the federal government will slap a failure to file penalty on your account. This fee adds 5% of the unpaid taxes for each month your tax return is late., up to a maximum of 25%.

The truth is, you’re better off starting on your taxes — or getting your paperwork to an accountant — once you receive your W-2s and other tax-related documents in late January.

This should give you plenty of time to submit your returns or request an extension well in advance of the mid-April deadline to avoid one of the most common tax-filing mistakes.

2. Choosing the Wrong Filing Status

• Single
• Married filing jointly
• Married filing separately
• Head of household
• Qualifying widow(er)

Although the categories seem fairly straightforward, many taxpayers make the wrong choice. That’s a shame, because choosing the correct filing status can mean the difference between getting a refund or paying additional taxes. It can even determine if you need to file a return at all.

So, if you’re unsure which status to select, do yourself a favor and use the IRS’s free online tool to help you decide. It’s one of the easiest miscues to prevent.

3. Entering Information Incorrectly

Even when we try to be careful, humans make mistakes. It’s no different with tax returns — especially if you’re doing them yourself.

Simple mistakes like entering your Social Security number or tax ID incorrectly, misspelling your name, or writing illegibly (if you don’t file online) can create problems when the IRS tries to process your return. To sidestep these common issues, be sure to:

• Enter identifying information and account numbers correctly
  
• Confirm the figures in each box on your return match what’s on your W-2 
  
• Review last year’s return to verify that any transferred information is accurate
  

Even though tax preparation software can improve the accuracy of your return, it won’t catch errors you make while entering data. That’s why you might consider hiring a tax professional to review your tax returns or even handle the entire process for you.  

4. Messing Up the Math

Remember in elementary math class when you’d get an entire problem wrong because you forgot to carry the one to the next column? Scores of taxpayers make similar mistakes each year, prompting the IRS to flood the mail service with math error notices.

To be fair, math errors encompass an array of snafus, some of which have nothing at all to do with arithmetic. Mistakes can range from addition and subtraction gaffes to omitted entries and insufficiently supported claims — and any number of blunders in between.

• Owing more taxes
• Receiving a smaller refund
• Getting a larger refund than you expected

Either way, you have 60 days to respond if you think a math error notice is incorrect. Otherwise it’s assumed you agree with the corrections.

All of this underscores the fact that taking your time to check your calculations, using tax software that crunches the numbers for you, or hiring a tax professional to handle everything are all good ways to keep from messing up the math on your returns.

5. Missing Tax Deductions or Tax Credits

One of the (few) cool things about the tax code is that it allows you to claim a standard deduction or itemize various expenses to help lower your overall tax bill.

If you choose the standard deduction, you can automatically subtract a predetermined amount from your returns based on your filing status. Here are the standard deductions for 2024:

• Single or married and filing separately: $14,600
• Married filing jointly or qualifying surviving spouse: $29,200
• Head of household: $21,900

Taxpayers who are 65 and older or blind qualify for these additional amounts on top of the standard deduction:

• $1,950 for single or head of household; $3,900 if both 65+ and blind

• $1,550 for married taxpayers or qualifying surviving spouse

Although taking the standard deduction is the easiest option, it may not always be the best one based on your situation.

• State and local income taxes
• Real estate and personal property taxes
• Home mortgage interest
• Casualty, disaster, or theft losses
• Investment interest expenses
• Business use of your car or home

While deductions help you save by reducing your taxable income or tax rate, tax credits — which are also easy to miss — can decrease the amount of tax you have to pay, increase your refund, or in some cases, provide a refund even if you don’t owe any taxes.

• Family and dependent credits
• Income and saving credits
• Homeowner credits
• Healthcare credits
• Education credits

Bottom line: There are countless deductions and credits available, and you’re leaving money on the table if you don’t take advantage of all that you’re entitled to.

Tax software or an accountant will walk you through identifying the ones that you qualify for and filling out the appropriate paperwork.

Or, you can use the IRS’s Interactive Tax Assistant to determine if you’re eligible for specific deductions and credits.

6. Forgetting to Sign Documents

No big deal if you forget to sign and date your tax returns, right? Actually, it is. The way the IRS sees it, an unsigned tax return isn't valid.

If you realize you filed your taxes without scribbling your John Hancock everywhere it’s required, you can print or fill out another copy, sign and date it, and mail it to the IRS. IRS processors will discard the unsigned version and use the new copy. Another option is to wait for the IRS to return your original tax forms, sign them, and then mail them back.

Of course, you can avoid the situation altogether by doing your taxes electronically and digitally signing the documents before submitting them to the IRS.

7. Filing by Mail

• Send their tax return to the wrong IRS office
• Forget to include important documents
• Arrange tax forms in the wrong order
• Neglect making copies of their returns
• Overlook enclosing a check or other payment type for taxes owed
• Fail to put enough postage on the envelope

Aside from checking and rechecking your returns (which you should undoubtedly do), the simplest way to eliminate these and any other mailing mishaps is to file your tax returns electronically through the IRS website or use tax software.

The Takeaway

Filling out and submitting your tax returns isn’t the time to get sloppy or impatient. By being deliberate and persistent, combing through your deductions and credits, and double-checking all your information, you can bypass many blunders that trip up others. That’s a tax-planning approach that can pay dividends in any season.