- ChatGPT's a useful research and drafting tool, but it can't file to HMRC or Companies House, can't be your authorised agent, and carries no liability when it gets a figure wrong.
- You can file plenty yourself for free, including your Confirmation Statement, Self Assessment registration and a simple Self Assessment return, and for a dormant or very simple company that might be all you need for now.
- You stay personally responsible for what's filed no matter what produced the numbers, and a private company that files accounts late faces a Companies House penalty of £150 to £1,500 that doubles for a second late year running.
Whether you need an online accountant, ChatGPT or a traditional accountant comes down to your business structure, your income, and whether you’re VAT-registered.
A dormant company or a simple sole trader under the £90,000 VAT threshold can often get by on ChatGPT plus HMRC’s free filing services. Register for VAT, hire someone, or start mixing salary with dividends, and an online accounting service starts to earn its fee. Here’s how the three stack up, and where each one breaks.
Worried you’re getting your company’s numbers wrong on your own?
ChatGPT, an online accountant, or a traditional firm: which do you need?
ChatGPT’s for understanding and drafting. An online accounting service or a traditional firm is for the filing, the liability and the judgement calls.
Most people treat the choice as permanent, and it isn’t. Plenty of business owners start with a spreadsheet and a chatbot, then bring in an accountant the year things get complicated. The three options sit at different points on the same journey, and the right answer changes as you grow.
How do the three options compare side by side?
Here’s what each option costs, what it does, and who carries the risk when something’s wrong.
| What matters | ChatGPT / AI tools | Online accounting service | Traditional high-street firm |
|---|---|---|---|
| Typical cost | Free or a low monthly subscription | Monthly fee, often billed annually | Monthly retainer or annual fee, usually higher |
| What it does | Explains, drafts, sanity-checks; doesn’t file | Bookkeeping, accounts, tax returns, filing | Bookkeeping, accounts, tax returns, filing |
| Who checks the work | You do, entirely | A qualified accountant | A qualified accountant |
| Who’s liable to HMRC | You, always | You, but with professional advice behind you | You, but with professional advice behind you |
| Can be your HMRC agent | No | Yes | Yes |
| Speed of response | Instant, but unverified | Usually same or next working day | Varies; often year-end only |
| When it’s wrong | You carry the penalty alone | Corrected, with indemnity behind the advice | Corrected, with indemnity behind the advice |
That “who’s liable to HMRC” row says the same thing three times, because the answer never changes. It’s the point most people skip, so it’s worth pulling out on its own.
What is ChatGPT actually good at for your accounts?
Plenty, and it’s worth being straight about it. AI tools handle these well:
- Explaining jargon. Ask what a Confirmation Statement is, or the difference between a director’s loan and a dividend, and you’ll get a plain-English answer in seconds.
- Drafting. A first pass at an expenses policy or a plain summary of HMRC guidance.
- Sanity-checking. A decent second opinion on a calculation you’ve already done yourself.
- Teaching you the basics. A patient tutor when you want to learn what a term means, not just be told the answer.
As one business owner put it: “I like to do this myself because I want to learn how it works.” ChatGPT’s a good study partner for that person. The case against leaning on it isn’t that it’s stupid; it’s about what happens the moment you move from understanding to filing.
What ChatGPT can’t do for a UK limited company
This is where the limits bite. ChatGPT can’t:
- File anything. It produces text, and text isn’t a submission to HMRC or Companies House.
- Be your authorised agent. Only a person or firm can be authorised to deal with HMRC on your behalf through the 64-8 process.
- Keep up with changing figures. The VAT registration threshold is £90,000 and Corporation Tax runs 19% to 25%, but a model on older data states superseded figures with total confidence.
- See your history. It doesn’t know your prior-year accounts, so it can’t spot the carried-forward loss or opening balance that changes everything.
- Carry the risk. No professional indemnity, no regulator, no one to appeal to. The bill lands on you.
Who’s responsible if the numbers are wrong?
You are. As the director of a UK limited company you’re personally responsible for what gets filed, whether a spreadsheet, a chatbot or a junior bookkeeper produced the numbers. If the accounts are late or wrong, Companies House and HMRC come to you.
The figures aren’t trivial. A private company that files its annual accounts late faces an automatic Companies House penalty on a sliding scale:
| How late the accounts are | Penalty (private company) |
|---|---|
| Up to 1 month | £150 |
| 1 to 3 months | £375 |
| 3 to 6 months | £750 |
| More than 6 months | £1,500 |
Those bands come straight from GOV.UK, and they double if you file late in two consecutive years. We break down every fine in more detail in our guide to HMRC and Companies House fines.
That’s before HMRC’s separate regime for a late Corporation Tax return. The two regulators don’t talk to each other, so one missed year-end can trigger both at once. “ChatGPT told me the threshold was different” isn’t an excuse Companies House will accept.
What can you genuinely do yourself, for free?
Plenty, and hiding that would be the fastest way to lose your trust. If your situation’s straightforward, you can handle these directly with the regulator at no service cost:
- File your Confirmation Statement with Companies House.
- Register for Self Assessment with HMRC.
- File a simple Self Assessment return yourself.
- Register for VAT when you cross the threshold.
You’ll still pay unavoidable government fees, the £50 digital Confirmation Statement fee for example, but those are charges you’d pay through an accountant anyway. For a dormant company, or a sole trader well under the VAT threshold with a handful of transactions a month, this can be the whole job. If that’s you, keep your money and revisit the decision when something changes.
TIPQuick gut-check: if you can name the last three things you filed and you weren’t sweating when you clicked submit, you’re probably fine doing it yourself for now. If you can’t, that unease is usually the signal it’s time to get help.
When does doing it yourself start to cost you money?
The maths flips at fairly predictable moments. Watch for these:
- VAT registration. Once you cross £90,000 in turnover, VAT returns and reclaim rules get fiddly fast, and mistakes are expensive.
- Your first employee. Payroll, PAYE and pension auto-enrolment are a real compliance burden with real deadlines.
- Dividends alongside salary. Getting the salary-and-dividend mix right is where a good accountant often saves more than their fee.
- R&D or investment relief claims. R&D tax relief, SEIS and EIS reward getting the paperwork exactly right and punish getting it wrong.
- A mistake in a prior year. The moment last year’s figures are off, this year’s get harder, and an AI tool that can’t see your history is a false economy.
Recognise more than one of these? DIY’s probably stopped saving you money and started costing it. As one business owner told us, “I’m not a professional bookkeeper.” You don’t have to be; you just have to know when to hand it over.
A traditional accounting firm: what do you get and what do you miss?
A high-street firm suits business owners who value an in-person relationship. Here’s the honest trade-off:
None of that makes a traditional firm wrong. It makes it worth asking how often you’ll actually hear from them.
Online accountant vs traditional accountant: what to ask before you sign up
An online service pairs qualified accountants with software that handles the repetitive work, usually at a clearer price than a traditional firm. If you want the detail, it’s worth reading up on how online accounting works in the UK first. Before you commit, ask:
- Who actually does the accounting? In-house employees, or subcontracted to a third party?
- Are the accountants UK-qualified? And can you see their credentials?
- Will you have one named contact? Or a rotating support queue?
- How fast do they respond? Same day, next day, or only at year-end?
The first question matters most. Some providers, particularly formation-led ones, outsource the work, so the person handling your numbers may not be in-house or someone you can build a relationship with. The answer tells you a lot about the quality you’ll get.
Can I just do this myself?
Sometimes, genuinely, yes. If your company’s dormant or your affairs are very simple, you can handle the filings yourself for free and there’s no shame in it. This isn’t a trick question with a hidden “but you should really pay us” at the end.
“Yes” becomes “you probably shouldn’t” when the cost of a mistake outgrows the cost of help, and that arrives with VAT registration, your first payroll, a salary-and-dividend structure, or a relief claim. Below that line, do it yourself and keep learning. Above it, a professional’s fee is cheaper than the penalty for getting it wrong, and usually cheaper than the tax you’d overpay by not knowing the efficient route.
Where an online accountant fits: in-house people, plus technology
Sleek pairs qualified in-house accountants with technology that handles the repetitive, easy-to-forget parts. The accounting’s done in-house rather than outsourced, so the person who knows your file is a real, named contact you can actually reach.
The technology stops things being missed: the deadlines, the thresholds, the small filings that slip when you’re busy. The human handles the judgement calls software can’t make.
You don’t have to choose between a person and good tools; the best setup uses both. You can see what our plans include rather than guess.
Which option fits your business? Four common situations
General advice is less useful than concrete cases, so here are four:
Notice none of these says “hire a firm no matter what.” The recommendation tracks your actual situation, which is the only sensible way to make the call. When you’re ready, a limited company accountant can take the compliance load off your plate.
How Sleek helps you choose the right support for your business
The honest answer to “ChatGPT, online accountant or traditional firm?” is that it depends on where your business is right now, and it’ll change as you grow.
Sleek’s the human-plus-technology option for the point where doing it yourself stops paying off: qualified in-house accountants and one named contact, not a rotating queue or an outsourced desk. Not sure which column you’re in? Tell us your turnover and how many people you pay, and we’ll tell you straight whether you need us yet.
Talk to a UK accountant about your company
See what’s included in our plans and get a straight answer on whether you need us yet.
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FAQs on Online Accountant vs ChatGPT
Can ChatGPT do my limited company accounts?
No. ChatGPT can explain concepts, draft documents and sanity-check a calculation, but it can’t prepare filed accounts or submit anything to HMRC or Companies House. It has no access to your bank feeds or prior-year figures, and it gives confident answers even when its data’s out of date. Treat it as a research assistant, not an accountant.
Do I actually need an accountant, or can I do it myself?
For a dormant company or a simple sole trader under the £90,000 VAT threshold, you can genuinely do it yourself for free. You’re likely to need help once you register for VAT, run payroll, mix salary with dividends, or make a relief claim. The deciding factor is when the cost of a mistake grows larger than the cost of the help.
Is it legal to file my own company accounts?
Yes, it’s completely legal to file your own accounts and returns. UK law makes the director personally responsible for filing, but it doesn’t require you to use an accountant to do it. The risk isn’t legal permission; it’s accuracy, because you carry the penalty if the figures are wrong.
What happens if my accounts are wrong because I used AI?
You’re liable, not the tool. A private company that files annual accounts late faces a Companies House penalty of £150 to £1,500 depending on how late, doubling if you’re late two years in a row, and HMRC runs a separate regime on top. “The AI gave me the wrong figure” isn’t a reasonable excuse either regulator will accept.
Can an AI tool be my authorised agent with HMRC?
No. Only a person or firm can be authorised to act on your behalf with HMRC, through the 64-8 process. An AI tool can’t hold that authorisation, file on your behalf, or deal with HMRC correspondence. If you want someone acting as your agent, it has to be a human or a firm.
What can I file myself for free?
You can file a Confirmation Statement, register for Self Assessment, file a simple Self Assessment return, and register for VAT, all directly with the regulator at no service cost. You’ll still pay unavoidable government fees, such as the £50 digital Confirmation Statement fee, but no intermediary’s required for a straightforward company.
At what point should I stop doing my own books?
When any of these arrive: VAT registration, your first employee, a salary-and-dividend structure, or an R&D, SEIS or EIS claim. Each one raises both the complexity and the cost of getting it wrong. If you already recognise more than one, professional help has probably moved from optional to worth every penny.
