Self Assessment Accountants
Self Assessment accountants help UK taxpayers file their Self Assessment tax return correctly and on time — whether you are self-employed, a landlord, a company director, or have income HMRC needs to know about.
What the service covers
Self Assessment accountants take care of your tax return from start to finish. Our work covers:
- Self Assessment tax returns — preparing and filing your return, including income from self-employment, employment, property, savings and investments.
- Registering for Self Assessment — telling HMRC you need to file, and getting your Unique Taxpayer Reference (UTR).
- Allowable expenses and reliefs — checking what you can claim, so you do not pay more tax than you should.
- Tax bills and payments on account — working out what you owe, when it is due, and planning for payments on account.
- Capital gains and foreign income — reporting capital gains, foreign income and other income that belongs on your return.
- HMRC letters, penalties and enquiries — help with late-filing penalties, HMRC letters and enquiries about your return.
See our plain-English guide to Self Assessment tax returns for 2025-26.
Who it is for
Self Assessment accountants are for anyone who has to file a tax return. This service is for:
- Self-employed people and sole traders — if you work for yourself, your Self Assessment return covers your trading income and allowable expenses.
- Landlords — if you receive rental income, you usually need to report it through Self Assessment.
- Company directors — directors who need to file a personal tax return alongside their company accounts.
- People with other income — including capital gains, foreign income, savings and investments, or income over £100,000.
- People who have missed a deadline — if your return is late or you have received a penalty, we help you file and deal with HMRC.
How it works
Here is how working with Self Assessment accountants usually goes:
- Contact us — tell us about your income and what you need help with, such as a tax return, a penalty or a late return.
- We review your records — we look at your income, expenses and deadlines to see where you stand.
- We agree the work and the fee in writing — you know what is included and what it costs before we start.
- We prepare and file your return — your Self Assessment tax return is prepared, checked with you, and filed with HMRC on time.
- We keep you on track — we remind you about deadlines, explain what you owe, and answer your questions through the year.
Typical fees
Typical UK market averages for 2026, based on published competitor fee guides — not a fixed quote. Your exact fee depends on your records and complexity; contact us for a written quote. All fees exclude VAT unless stated.
| Service | Typical UK average | What affects the price |
|---|---|---|
| Self Assessment tax return | £150–£400 (average around £250) | How many sources of income you have and how tidy your records are |
| Simple tax return | £150–£250 | One main source of income and straightforward records |
| Complex tax return | £350–£500+ | Property, capital gains, foreign income or several income sources |
Why choose us
- Plain-English explanations — we explain what you owe and why, without jargon.
- Fixed fees agreed in writing — you know the cost before we start, with no surprises.
- Deadlines handled for you — we file your return on time and remind you about payment dates.
- All your income covered — self-employment, property, savings, investments and foreign income in one return.
- Help if you are behind — we help with late returns and penalties, and deal with HMRC for you.
Frequently asked questions
How much does a Self Assessment tax return cost?
A Self Assessment tax return typically costs £150–£400 (average around £250). Simple returns are usually £150–£250, and complex returns — for example with property, capital gains or foreign income — are usually £350–£500+. Your exact fee depends on your records and complexity — contact us for a written quote.
When is the Self Assessment deadline?
Online Self Assessment tax returns are due by 31 January after the end of the tax year, and any tax you owe is also due by 31 January. Paper returns are due earlier, by 31 October.
Do I need to file a Self Assessment tax return?
You need to file if HMRC asks you to, or if you have income that is not taxed at source — for example self-employment income, rental income, capital gains or foreign income. If you are not sure, contact us and we can check.
Can you help if my tax return is late?
Yes. We can prepare and file your late return, work out what you owe, and help you deal with any penalties from HMRC.
What do I need to give you?
Your income and expense records, such as invoices, bank statements, P60s or P45s, and details of any other income. We will tell you exactly what we need when we review your records.
Read our guide to Self Assessment tax returns for 2025-26.
Talk to us about your Self Assessment
If you would like help with your Self Assessment tax return, contact us or email info@accountingtaxadvisor.co.uk.