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Yes, an accountant can take your whole Self Assessment off your hands, from working out what you owe to filing it with HMRC as your agent. Most people hire one for the same reason: the return looks simple until it is not, and a wrong figure is expensive to unpick later. Below is what an accountant for self assessment actually does for you, what it tends to cost you to get the return wrong on your own, and the cases where you are fine filing it yourself.
A Self Assessment return reports the income you earned over the tax year and the expenses or reliefs you want to claim against it. You file it once a year, and the figures have to reconcile.
You are not legally required to use one. HMRC lets anyone file their own return. You tend to want an accountant once your tax affairs stop being straightforward: you run a business, you have rental or foreign income, you have capital gains to report, your income crosses into payments on account, or you have had a year messy enough that a mistake feels likely.
If your return is one employment and a bit of savings interest, you can probably manage it alone. The further you sit from that, the more an accountant earns their fee.
Is it worth getting an accountant for Self Assessment?
For most self employed people and landlords, yes. The fee usually buys back more than it costs, in two ways. You stop losing reliefs and allowable expenses you did not know to claim, and you stop making the errors that trigger an HMRC enquiry. Here is the rough trade-off.
| Filing it yourself | Using an accountant |
|---|---|
| Free in cash. Costs your time, and you carry the risk of missed reliefs and filing errors. | A fee you can usually fix in advance, in exchange for reclaimed time, claimed reliefs, and someone accountable for the figures. |
The honest version: if your return is simple, doing it yourself is fine and an accountant adds little. If it is not, the fee is rarely the expensive part of the equation.
What an accountant actually does on your return
Cuts the risk of errors and HMRC enquiries
File the return with a wrong figure and you risk an HMRC enquiry, which is slow and stressful to sit through. An accountant checks the numbers reconcile before anything is submitted, works alongside your bookkeeping software, and keeps a clean record behind every entry. If HMRC does come back with a question, your accountant answers it as your agent.
Finds the reliefs and expenses you would miss
This is where the fee tends to pay for itself. An accountant knows which expenses you can legitimately claim and which reliefs apply to your situation, so you are not handing HMRC more than you owe. The money you keep goes back into the business or your own pocket.
Handles the deadlines and the admin
Miss the online filing deadline and HMRC charges an automatic penalty even if you owe no tax. An accountant tracks the dates, including any payments on account, and files in good time so you are not paying for being late.
Deals with HMRC on your behalf
Registered as your agent, an accountant can talk to HMRC directly, handle correspondence, and sort out anomalies before they grow into something worse. You stop being the one on hold to the helpline.
What you need to give your accountant
The smoother you want this, the better your paperwork. Most accountants will ask for your income records for the year, your business expenses with receipts, bank statements, details of any other income such as rent, dividends or foreign earnings, records of capital gains, your Unique Taxpayer Reference, and last year’s return if you have one. Hand that over early and the return is quick. Drip-feed it in January and it is not.
When you can file it yourself
An accountant is not always worth it, and pretending otherwise would be dishonest. If your only income is from one PAYE job with some savings interest, or a small side income under the trading allowance, the return is short and HMRC’s online system walks you through it. Use an accountant when the figures get real: business profit, property, gains, or anything you are not confident you have reported correctly.
Self Assessment support
Get your Self Assessment handled
If your return has moved past the simple stage, IBISS & CO files Self Assessment returns for self-employed people, landlords, company directors and high net worth individuals across London and the UK. We check the figures, claim what you are entitled to, and deal with HMRC as your agent.
Self Assessment FAQs
Can an accountant help with a tax return?
Yes. An accountant can prepare the whole return, check it reconciles, claim the reliefs you are due, and file it with HMRC for you. You can hand over as much or as little as you want, from a final review to the entire job.
Can an accountant file my Self Assessment with HMRC?
Yes. Once you authorise them as your tax agent, they can submit the return through HMRC agent services and deal with HMRC on your behalf afterwards.
How much does an accountant charge for a Self Assessment return?
It depends on how complex your return is. A simple return costs less than one with business accounts, property and capital gains behind it. Ask for a fixed quote up front so you know the fee before any work starts.
Do I still need an accountant under Making Tax Digital?
Making Tax Digital for Income Tax changes how returns are kept and submitted for those above the income threshold Making Tax Digital for Income Tax mandatory from 6 April 2026, £50,000 income threshold. If it applies to you, an accountant sets up compliant software and handles the quarterly submissions, which is more administration than the old annual return.
Muhammad Sufyan Moavia
Muhammad Sufyan Moavia, Chartered Tax Adviser and Fellow Chartered Certified Accountant at IBISS & CO.
He has 15 years experience in accounting and tax, advising individuals and business owners on personal tax, HMRC matters, IHT, CGT and tax planning.
Last review: July 2026
