Can ChatGPT do your tax return?
It will give you a confident, well-written answer in seconds, and more often than you might expect that answer will be wrong. HMRC does not accept “the AI told me” as a defence, so it is worth understanding the limits before you hand your tax to a chatbot.
By Bobby Gardiner·14 July 2026·6 min read
- AI is very good at sounding right, which makes it risky for tax, where a confident wrong answer costs you real money.
- It “hallucinates”, meaning that it invents allowances and reliefs that do not exist and quotes thresholds from tax years long past, and it does so with complete confidence.
- It does not know your situation, it cannot file anything or deal with HMRC, and it cannot be held responsible when something goes wrong, all of which an accountant can do.
- To use AI safely on tax you would need to be an accountant already, so in practice it saves the expert time without reducing the taxpayer's risk.
- A real, AAT-licensed accountant is accountable, keeps up to date and is paid to find what you would miss, which is the part a chatbot cannot provide.
You have probably already tried it: a quick question about your tax typed into ChatGPT, followed by an instant, confident and nicely written answer. We understand the appeal, because the tools are impressive and we use modern technology every day ourselves.
There is a considerable difference, though, between an AI that can write about tax and one that you can trust with your tax. On the second point, our view is that it is not there yet. Below we explain why that matters and where it tends to go wrong.
Why a confident wrong answer is the dangerous kind
A search engine that does not know the answer will give you nothing useful, whereas an AI chatbot that does not know the answer will still produce a well-worded and authoritative-sounding reply. This is known as a “hallucination”: the model invents facts and presents them with complete confidence.
If you are asking for a holiday tip, that is harmless enough, but on a tax return the same habit can be expensive. If you ask about a relief the chatbot may invent one, and if you ask about an allowance it may quote a figure from three years ago. It gives no indication of doubt and sounds as sure when it is wrong as when it is right, so unless you already know the correct answer you have no way of telling which is which.
Tax rules change every year, and the AI is working from the past
Tax rules change constantly. Dividend tax rates changed in April 2026, Making Tax Digital for Income Tax is being rolled out now, and allowances, thresholds and the rules around them shift with every Budget. An AI model is trained on a snapshot of the internet from months or years earlier, so it will give you last year's figures, or the year before's, without mentioning that they have changed.
If you file on out-of-date figures, the mistake is treated as yours and the chatbot bears none of the consequences. Any penalties, interest and enquiry letters come to you, and “but ChatGPT said” carries no weight at all with HMRC.
It does not know you, and the savings depend on knowing you
An accountant's job is to apply the tax rules to your own situation, meaning your mix of income, your expenses, how your business is structured and what you are planning next. The savings come from that work, and a general-purpose chatbot cannot see any of it.
It does not know that you took dividends instead of salary, that your van is 80% business use, that you have a rental property coming next year, or whether you would be better off as a sole trader or a limited company. It cannot ask the right follow-up question, because it does not know that the question matters. A good accountant knows which questions matter, and will find savings that you did not realise were available.
It cannot file, sign or speak to HMRC for you
Even if the AI got every figure right, it has only produced text on a screen, and the return still has to be dealt with. It cannot file your return or sign it, it cannot ring HMRC when something is wrong, chase your refund, register you for a scheme or represent you in an enquiry, and it cannot spot the letter you should have acted on or the deadline you are three days from missing.
- Nobody is accountable for what a chatbot tells you, whereas we carry professional indemnity insurance, answer to a regulator, and will be there when HMRC writes to you.
- A chatbot is not regulated by anyone, whereas AR Gardiner & Co. is AAT-licensed and supervised for anti-money-laundering purposes, so there is oversight of the work we do for you and we have a stake in getting your numbers right.
- A chatbot has no relationship with you, whereas when you call us the person who answers is Bobby, who already knows your business, and you will never find yourself talking to a bot.
The uncomfortable irony
The catch is that to use AI safely for tax you need to be able to spot when it is wrong, which means understanding tax well enough to check the answer yourself. The people best placed to use these tools are therefore accountants. For everyone else, there is no way of checking the answer, so the risk goes unnoticed, and nothing has been saved because the checking still has to be done by someone who knows the rules.
We are not against AI, and we use modern software every day to work faster and to keep your records accurate. There is a clear difference, however, between technology that helps an accountant do the job and a chatbot that is standing in for one. For your own return, the sensible arrangement is one where a named person is accountable for the result.
Let a real accountant handle it.
You get fixed fees, plain English and a named person who is accountable for your numbers, which no chatbot can offer. Book a free, no-obligation review and we will tell you plainly where we can save you money.
Common questions
Can I really do my own tax return with ChatGPT?
You can ask it questions and it will answer confidently, but it cannot file the return, it cannot be relied on to know the current year's figures, and it cannot see your particular situation. The danger is that its mistakes look identical to its correct answers, so you will not know which is which, and where money is at stake we would not recommend relying on it.
Is AI ever useful for tax and accounting?
Yes, it can be useful in the right hands. We use modern software and automation every day to work faster and keep records accurate. The difference is that a qualified person checks the output, applies judgement and takes responsibility for the result. Used in that way it saves an accountant time. Without a qualified person checking the result, the risks described in this article apply.
What if I file a wrong return because AI gave me bad information?
The responsibility is entirely yours. HMRC can charge penalties and interest and can open an enquiry, and “the AI told me” is not an accepted defence. When we prepare your return we stand behind it, we are insured, and we are regulated by the AAT.
Why use AR Gardiner & Co. instead of a cheap online tool?
Because you get a real, AAT-licensed accountant who knows your name and your numbers, agrees a fixed fee in advance, keeps up with every rule change and looks hard for ways to save you tax. You deal directly with Bobby Gardiner; there is no call centre and no chatbot involved.