Can AI do my taxes?
An AI model can read your documents, explain a rule and add the numbers up. It cannot be the preparer of record. A return prepared for pay carries a signature and a PTIN, and the rules governing preparers are written for people. Whatever AI produces, you file as self-prepared, under penalty of perjury.
The interesting question is not whether a model can compute a tax. It can. The question is what happens eighteen months later, when a notice arrives and someone has to answer for the figure.
| AI does your taxes | A preparer does your taxes | |
|---|---|---|
| Reads your documents | Yes | Yes |
| Computes the tax | Yes | Yes |
| Signs the return | No | Yes, with a PTIN |
| Named on the return | No | Yes |
| Can be penalised for the position taken | No | Yes, under IRC 6694 |
| Can answer an IRS notice for you | No | Yes, if credentialed |
| Carries the accuracy risk | You do | You do, with recourse |
That last row is the one people miss. Using AI does not move the liability anywhere. It removes the second name from the page.
The signature line
A paid preparer has to sign the return and put a Preparer Tax Identification Number on it. The IRS states it flatly: anyone who prepares or assists in preparing federal tax returns for compensation must have a valid PTIN before preparing returns (PTIN requirements).
The agency is equally flat about who that is. Its PTIN guidance defines a signing tax return preparer as the individual tax return preparer who has the primary responsibility for the overall accuracy of the preparation of the return, and requires that every individual who prepares or assists in preparing a return for compensation hold his or her own PTIN. Not the firm's. Not the software's. A named human being, holding a number that traces every return they touched back to them.
A preparer who skips that step has a name at the IRS. It is a ghost preparer, and it sits on the Dirty Dozen list of tax scams. The penalties for it are small but real: for returns filed in 2025, $60 for each unsigned return and $60 for each missing PTIN, capped at $31,500 apiece and adjusted every January (Tax preparer penalties). The understatement penalties behind them are not small. Under IRC 6694 a preparer who takes an unreasonable position owes the greater of $1,000 or half the fee, and willful or reckless conduct raises that to $5,000 or three quarters of the fee.
Read that list again as a description of what a signature buys. It is not a formality. It is the mechanism by which somebody other than you is exposed when the return is wrong.
Circular 230, the rulebook for practice before the IRS, is built on the same premise. It covers attorneys, certified public accountants, enrolled agents, enrolled actuaries and enrolled retirement plan agents. Every category is a person, because every sanction in the document (censure, suspension, disbarment from practice) only bites on someone with a career to lose.
The declaration you sign
Above the signature line on Form 1040 sits a sentence declaring, under penalties of perjury, that you have examined the return and that it is true, correct and complete to the best of your knowledge.
You are attesting that you looked. Not that a tool looked.
Which is why "the AI told me so" is a weak position rather than a shield. The Taxpayer Advocate Service, the IRS's own internal watchdog, states the rule without qualification: taxpayers are ultimately responsible for the information reported on their tax returns.
What a wrong number costs
| If the return is | The exposure |
|---|---|
| Right | Nothing |
| Wrong, honest mistake | The tax, plus interest from the due date |
| Wrong, negligent or a substantial understatement | Add 20% of the underpayment (IRC 6662) |
| Wrong, and you knew | Civil fraud penalty, and in rare cases prosecution |
A substantial understatement means understating the tax by the greater of $5,000 or ten percent of what you owed. For a household with a mortgage, a side business and some investment income, that is not an exotic threshold. It is one misread K-1.
Where AI genuinely helps
None of this makes AI useless at tax time. It is good, sometimes very good, at the parts that are language rather than judgment:
- Explaining what a form is and why you received it
- Turning IRS prose into something readable in one pass
- Listing what to gather before an appointment
- Sanity-checking arithmetic you have already done another way
- Drafting the question you want to ask a human
It is weakest exactly where the money is: which of your facts matter, which of several defensible treatments to pick, and what you can prove if asked. Those are the parts a preparer is paid for, and they are the parts that get signed for.
The IRS arrived at the same place from the other direction. In the 2026 Dirty Dozen, the first year artificial intelligence appeared on that list at all, the advice was not to rely on AI-generated responses to complex tax questions, and to verify any calculation or information an AI provides.
Verify it against what, though. The warning leaves that open, and for most people the honest answer is a person who signs.
Common questions
Can AI file my return for me?
No system files on its own authority. Software transmits a return you have signed and authorized. The signature block still reads self-prepared unless a paid preparer signed it, and the IRS defines a signing preparer as the individual who has primary responsibility for the overall accuracy of the return.
Is it legal to use AI to prepare my own return?
Yes. You may prepare your own return however you like, on paper, in software, or with a chatbot reading over your shoulder. The preparer rules apply to people paid to prepare returns for others, not to you doing your own.
If AI gets it wrong, is that a defense against a penalty?
The IRS has not recognised it as one. The Taxpayer Advocate Service puts it plainly: taxpayers are ultimately responsible for the information reported on their tax returns. The accuracy-related penalty is 20 percent of the underpayment.
What does the IRS say about using AI for taxes?
In the 2026 Dirty Dozen it warned that taxpayers should not rely on AI-generated responses to complex tax questions, and that they should verify any calculations or information provided by artificial intelligence. That was the first year AI appeared on the list.
Does any of this apply to state returns?
The signature and preparer rules described here are federal. States run their own preparer registration, and several of them, California and Oregon among them, add requirements on top of the federal ones.
Sources
- IRS, PTIN requirements for tax return preparers
- IRS, Frequently asked questions: Do I need a PTIN?
- IRS, Don't be victim to a ghost tax return preparer
- IRS, Tax preparer penalties
- IRS, Choosing a tax professional
- Treasury Department Circular No. 230, Regulations Governing Practice before the Internal Revenue Service
- IRS, About Form 1040, U.S. Individual Income Tax Return
- IRS, Accuracy-related penalty
- IRS, Dirty Dozen tax scams for 2026 (IR-2026-30)
- Taxpayer Advocate Service, Is AI-generated tax advice making the grade?
Written by Tax Shop in Lone Tree, Colorado, where returns are prepared and signed by an Enrolled Agent. Checked against the sources above on . Penalty amounts and inflation-adjusted figures change each January, and every return is different, so this is not advice about your own situation.