TurboTax calculates your refund based on what you enter, not on what maximizes your return

TurboTax is a tax preparation tool that walks you through questions and fills in forms based on your answers. It does not search for deductions you did not mention, find credits you did not know existed, or second-guess the income figures you provide. If you miss a deduction, forget to report a tax credit, or enter a number wrong, your refund will be smaller than it could have been — and TurboTax will show you exactly what you told it to show.

The software is also designed to move you through the process quickly. That speed works against thoroughness. Many people skip sections they do not immediately recognize, miss questions buried in dropdown menus, or do not realize that a life event (a child born, a home purchased, a job change) opens up deductions or credits they have never heard of. TurboTax does not flag these gaps on its own.

A tax professional — a CPA, enrolled agent, or tax attorney — will often find deductions and credits that TurboTax users miss, sometimes by thousands of dollars. That does not mean TurboTax is broken. It means you are responsible for knowing what to tell it.

Key Takeaways

  • TurboTax only includes deductions and credits you actively enter or that the software specifically asks about; it does not search for ones you do not mention.
  • Common missed deductions include home office expenses, business mileage, education costs, medical expenses above the threshold, and charitable donations.
  • Tax credits for children, education, energy-efficient home improvements, and earned income are easy to overlook if you do not read every screen carefully.
  • A tax professional can often find deductions and credits that cost you hundreds or thousands in refund money, and their fee may be tax-deductible.
  • Comparing your TurboTax return to one prepared by a professional is the only way to know whether you are leaving money on the table.

Deductions TurboTax users commonly skip

TurboTax asks about major life events and income sources, but it does not ask about every possible deduction. If you are self-employed, work from home, drive for work, or have significant medical or charitable expenses, you may pass through sections without entering amounts that would lower your taxable income.

Home office deduction is one of the most missed. If you use part of your home exclusively for business, you can deduct a portion of rent, utilities, internet, and depreciation. TurboTax has a section for this, but many people do not realize they may have access to or do not fill it in completely. The deduction can range from a few hundred to several thousand dollars depending on your home size and business use.

Business mileage is another. If you drive for work — client visits, job sites, deliveries — you can deduct the mileage at the IRS rate (which changes yearly). TurboTax asks about this, but only if you report self-employment income. If you are an employee who drives for work, the deduction was suspended for 2018 through 2025, but you should still know the rule applies to self-employed people and business owners.

Education expenses include tuition, fees, books, and supplies for yourself or a dependent. The American Opportunity Tax Credit and Lifetime Learning Credit are separate from the deduction, and TurboTax asks about both — but only if you navigate to the education section. Many people miss it entirely.

Medical and dental expenses above 7.5% of your adjusted gross income can be deducted. This includes insurance premiums you paid out of pocket, prescriptions, dental work, vision care, and medical equipment. The threshold is high, so this deduction helps mainly people with major medical bills or retirees who paid their own insurance. TurboTax has a section for it, but it is easy to skip.

Tax credits that disappear if you do not claim them

A tax credit is worth more than a deduction because it reduces your tax dollar-for-dollar, not just your taxable income. Missing a credit can cost you far more than missing a deduction of the same size.

Child Tax Credit is $2,000 per child under 17. TurboTax asks for your children's names and Social Security numbers, so if you have children, the software usually catches this. But if you have a child who does not live with you full-time, or if you are unsure whether you can claim them, you may skip the section or answer incorrectly.

Earned Income Tax Credit (EITC) is a refundable credit for people with low to moderate income. The amount depends on your income, filing status, and number of children. TurboTax asks about income, but the EITC section is easy to miss if you do not read every screen. For a single parent earning $40,000 with two children, the credit can be over $3,000.

Education credits — the American Opportunity Credit (up to $2,500) and Lifetime Learning Credit (up to $2,000) — are separate from the education deduction. You can claim one or the other, but not both for the same student in the same year. TurboTax asks about education expenses, but you have to navigate the right section to see the credits available.

Energy-efficient home improvement credit covers solar panels, heat pumps, insulation, and other upgrades. The credit is 30% of the cost (up to certain limits per item). If you made these improvements, TurboTax has a section for it, but many people do not know the credit exists and skip the question.

How TurboTax handles income you do not report

TurboTax relies on you to enter all income. The software does not pull data from your bank, brokerage, or payment apps. If you receive 1099 forms (from freelance work, investment income, or side gigs), you have to enter them manually. If you do not, your refund will be based on incomplete income, and the IRS will catch the discrepancy when it matches your return to the 1099s it receives.

The same applies to cryptocurrency gains, rental income, and cash payments. TurboTax cannot see these unless you tell it. Many people underreport income by accident — they forget a 1099, do not realize a payment counts as taxable income, or assume small amounts do not matter. A smaller refund now means a larger bill (plus penalties and interest) later when the IRS notices.

When a tax professional finds money TurboTax missed

A CPA, enrolled agent, or tax attorney will interview you about your life and finances in ways TurboTax does not. They ask follow-up questions, catch details you did not think were relevant, and know about deductions and credits specific to your situation.

For example, a professional might ask whether you donated a car, whether you paid property taxes, whether you had investment losses to carry forward, or whether you made estimated tax payments. They know the rules for home office deductions, rental property depreciation, and business expenses. They understand how marriage, divorce, adoption, or a job change affects your taxes. TurboTax asks some of these questions, but a professional asks all of them and knows how they connect.

The cost of hiring a professional ranges from $200 to $1,000 or more depending on the complexity of your return. If a professional finds $2,000 in missed deductions and credits, they have paid for themselves. Many people find that comparing a TurboTax return to one prepared by a professional reveals hundreds or thousands in differences.

How to check whether TurboTax is giving you the best refund

The only reliable way to know is to have your return prepared by someone else and compare. You do not have to file the second return — you can use it as a reference to see what you missed.

Start by gathering documents: all W-2s and 1099s, receipts for deductions (medical, charitable, business, education), mortgage interest statements, property tax records, and records of any major life events (marriage, birth, adoption, home purchase, job change). A tax professional can review these and prepare a return showing what you should have claimed.

If the professional's return shows a significantly larger refund, you can amend your TurboTax return using Form 1040-X (Amended U.S. Individual Income Tax Return). You have three years to file an amended return and claim a refund you missed. The IRS will process it and send you the difference.

If the professional's return shows the same or a smaller refund, TurboTax did its job correctly — you simply did not have the deductions or credits you thought you did.

Frequently Asked Questions

Does TurboTax automatically find all my deductions?

No. TurboTax asks about common deductions and credits, but only if you navigate to those sections and answer the questions. It does not search for deductions you do not mention or know about. If you skip a section or do not read every screen, you may miss deductions that apply to you.

Can I amend my return if TurboTax missed a deduction?

Yes. You can file Form 1040-X (Amended U.S. Individual Income Tax Return) to claim deductions or credits you missed on your original return. You have three years from the original filing date to file an amended return and receive a refund.

Is it worth paying a tax professional if I use TurboTax?

It depends on your situation. If your taxes are simple (one job, no side income, no major deductions), TurboTax usually captures what you owe. If you are self-employed, own a business, have significant investments, or have major life changes, a professional often finds deductions and credits that cost you hundreds or thousands in refund money.

What if I disagree with TurboTax's refund amount?

Review every section of your return to make sure you entered all income, deductions, and credits correctly. If you find an error, you can edit your return before filing. If you filed already and believe you missed something, file an amended return using Form 1040-X within three years.

Does TurboTax charge more if my refund is smaller?

No. TurboTax charges a flat fee based on the version you choose (Free, Deluxe, Premier, or Self-Employed). The refund amount does not affect the price you pay for the software.