Self Assessment accountants for your tax return
We prepare and file your Self Assessment tax return, go through every figure with you on a call before it goes to HMRC, and keep you clear of the deadlines. Everything comes to us from your phone.
ACCA qualified accountants with over 20 years in practice
Who has to file a tax return
You need to send a return if, in the last tax year, you were self employed as a sole trader and earned more than £1,000, you were a partner in a business partnership, or you had Capital Gains Tax to pay. Money from renting out property, foreign income and other income that has not been taxed can also mean a return.
The first £1,000 of trading income is tax free under the trading allowance. Once you go over it, you need to register for Self Assessment.
CIS subcontractors file one too. It is the return that sets the CIS taken from your pay against your tax for the year, and pays back anything taken over.
What we need from you
Photos from your phone or files by email are all it takes.
What came in
Your invoices or a list of jobs paid, bank statements for the business account, and your CIS statements if contractors paid you under the scheme.
How CIS refunds workWhat went out
Receipts and bills for your business costs, so nothing you are allowed to claim gets missed.
Any other income
Rent from a property, a P60 from a job, dividends or interest. All of it can change the tax you owe.
Last year's return, if you have it
So we can see your payments on account and carry anything forward correctly.
How it works
Send us your paperwork
Photos or files, whenever suits you, through the year or in one go.
We prepare the return
An accountant works through your income and costs and spots anything missing.
We go through it on a call
You see what you owe, or what is coming back, before anything is filed.
We file and remind you
We send the return to HMRC and tell you what to pay and when.
Key dates for the 2025/26 return
For the tax year 6/4/2025 to 5/4/2026, from GOV.UK.
| What | Rule or date | Source |
|---|---|---|
| Self Assessment registration | 5/10 after the end of the tax year (5/10/2026 for 2025/26) | GOV.UK (opens in a new tab) |
| Self Assessment paper return | 11:59pm 31/10/2026 (2025/26 return) | GOV.UK (opens in a new tab) |
| Self Assessment collect through PAYE code | Online return by 11:59pm 30/12/2026 | GOV.UK (opens in a new tab) |
| Self Assessment online return | 11:59pm 31/1/2027 (2025/26 return) | GOV.UK (opens in a new tab) |
| Self Assessment balancing payment and first payment on account | 31/1/2027 | GOV.UK (opens in a new tab) |
| Self Assessment second payment on account | 31/7 (31/7/2027 for 2026/27) | GOV.UK (opens in a new tab) |
| Payments on account rule | Each is half of last year's bill; not needed if last bill under £1,000 or more than 80% paid at source | GOV.UK (opens in a new tab) |
Penalties if you are late
Today's penalties for filing or paying late. From April 2027 a new system of points and percentage penalties applies to everyone who files a personal Self Assessment return.
| What | Rule or date | Source |
|---|---|---|
| Self Assessment late filing | £100; after 3 months £10 a day up to £900; after 6 months 5% or £300 (greater); after 12 months another 5% or £300 (greater) | GOV.UK (opens in a new tab) |
| Self Assessment late payment | 5% of unpaid tax at 30 days, 6 months and 12 months, plus interest | GOV.UK (opens in a new tab) |
| Self Assessment amendment | Within 12 months of the filing deadline | GOV.UK (opens in a new tab) |
| Overpayment relief | Up to 4 years after the end of the tax year (claim in writing) | GOV.UK (opens in a new tab) |
Start early
The weeks before 31/1 are the busiest of the year for tax returns. Sending your paperwork in the autumn gives you time to find anything missing and gives us time to check it properly, with no rush at the end.
Making Tax Digital for Income Tax also starts changing how returns work for people with higher incomes, from 6/4/2026 for qualifying income over £50,000.
Making Tax Digital
Find out when the new quarterly updates start for you, and what they involve.
Paid under CIS?
Your tax return is how the CIS taken from your pay comes back to you.
The tax rules on this page come from GOV.UK and HMRC guidance. Last checked .
Questions about Self Assessment
When is my tax return due?
For the 2025/26 tax year, an online return is due by 11:59pm on 31/1/2027 and a paper return by 31/10/2026. Any tax owed is also due by 31/1/2027.
What happens if I file late?
There is a £100 penalty straight away. After 3 months it becomes £10 a day, up to £900, and more after 6 and 12 months. Paying late brings its own penalties and interest.
What are payments on account?
Two advance payments towards next year's bill, each half of last year's, due by 31/1 and 31/7. You do not make them if your last bill was under £1,000 or more than 80% of your tax was taken at source.
Can I correct a return after it has been filed?
Yes, within 12 months of the filing deadline. After that, overpaid tax can still be claimed back in writing for up to 4 years after the end of the tax year.
I have just started working for myself. When do I register?
By 5/10 after the end of the tax year you started in, so by 5/10/2026 if you started during 2025/26.
Do I need a return if I only earn a little on the side?
Not if your trading income is £1,000 or less in the tax year, because the trading allowance covers it. Over £1,000, you need to register.
Get your tax return off your mind
Tell us a little about your income and we will send you a quote. Or book a free call if you would rather talk first.