File Your Self Assessment Tax Return Online
Let our experienced accountants prepare, calculate and file your Self Assessment tax return directly with HMRC. A straightforward online service with fixed fees from £299 + VAT.
- Prepared by UK accountants
- Filed directly with HMRC
- Fixed fees — no hourly billing
- Average turnaround 7–14 days
Need to File a Self Assessment Tax Return?
We prepare, calculate and file Self Assessment tax returns directly with HMRC for individuals across the UK. Our online fixed-fee service is designed for landlords, company directors, investors, sole traders and individuals with income or capital gains that need to be reported to HMRC.
You send us your information securely, we review your figures and prepare the appropriate Self Assessment return and supplementary pages. We calculate your tax position, send the completed return to you for approval and, once approved, submit it electronically to HMRC.
There is no need to visit an accountant's office. The process can be completed remotely from anywhere in the UK.
Who May Need to File a Self Assessment Tax Return?
Self Assessment is HMRC's system for collecting tax that has not already been fully dealt with through PAYE or another deduction at source. Your filing requirement depends on your circumstances, income and gains.
Self-Employed
Sole traders may need to file where gross self-employment income exceeds the relevant trading allowance or HMRC otherwise requires a return.
Landlords
UK and overseas property income can create a requirement to notify HMRC and report rental profits through Self Assessment.
Company Directors
Directors may need Self Assessment where they have untaxed income, dividends, capital gains or other circumstances requiring a return. Being a director alone does not automatically mean a return is required.
Capital Gains
Disposals of property, shares, cryptocurrency or other assets can result in taxable gains that need to be reported.
Savings & Dividends
Investment income, dividends and savings interest can create additional tax liabilities depending on the amount received and your circumstances.
Foreign Income
Overseas property, investments, pensions and other foreign income may need to be declared on a UK Self Assessment return.
Self Assessment Tax Return Filing from £299 + VAT
Select the band that matches the total relevant income and capital gains covered by your return. If your circumstances are particularly complex or exceed these limits, contact us for a quotation.
Small Self Assessment
- Income and capital gains up to £30,000
- Return preparation
- Tax calculation
- HMRC electronic filing
- Tax efficiency review
- Average turnaround 7–14 days
Medium Self Assessment
- Income and capital gains up to £100,000
- Return preparation
- Tax calculation
- HMRC electronic filing
- Tax efficiency review
- Average turnaround 7–14 days
Large Self Assessment
- Income and capital gains up to £250,000
- Return preparation
- Tax calculation
- HMRC electronic filing
- Tax efficiency review
- Average turnaround 7–14 days
More complex tax affairs may require a separate quotation. Please contact us before ordering if you are unsure which service applies.
What's Included in Our Self Assessment Filing Service?
Our service covers the preparation and electronic filing of your Self Assessment tax return rather than simply providing software for you to complete it yourself.
- Preparation of your Self Assessment tax return
- Relevant SA100 supplementary pages
- Review of income and allowable expenses
- Income Tax calculation
- Capital Gains Tax calculation where applicable
- National Insurance calculations where applicable
- Review of available tax reliefs
- Rental income review where applicable
- Dividend and investment income reporting
- PAYE income incorporated into the return
- Calculation of payments on account where applicable
- Tax payment information explained
- Completed return sent to you for approval
- Electronic filing directly with HMRC
- Confirmation once your return has been submitted
- Email support for straightforward queries
When Do I Need to File My Self Assessment Tax Return?
For most taxpayers filing the 2025/26 Self Assessment tax return, the normal online filing deadline is 31 January 2027.
| Self Assessment date | Normal deadline for 2025/26 |
|---|---|
| Tax year ended | 5 April 2026 |
| Register / notify HMRC where required | 5 October 2026 |
| Paper tax return | 31 October 2026 |
| Online Self Assessment return | 31 January 2027 |
| Balancing payment of tax | 31 January 2027 |
| Second payment on account, where applicable | 31 July 2027 |
Different deadlines can apply in certain circumstances, including where HMRC issues a notice to file late. Filing early gives you more time to understand the amount due and plan for payment.
What Do I Need to File a Self Assessment Tax Return?
The information required depends on your circumstances. We will tell you what we need, but the following are common records used to prepare a UK Self Assessment return.
| Income or transaction | Typical information required |
|---|---|
| Employment | P60, P45 and P11D information where applicable |
| Self-employment | Sales, business expenses and relevant accounting records |
| Rental property | Rental income, property expenses and finance cost information |
| Company dividends | Dividend vouchers or details of dividends received |
| Savings | Bank and building society interest |
| Capital gains | Purchase and disposal details plus associated costs |
| Foreign income | Details of overseas income and any foreign tax suffered |
| Pensions | Taxable pension income and relevant pension contribution information |
| Tax reliefs | Details of eligible contributions, donations or other relief claims |
How We File Your Self Assessment Tax Return
Our service is completely online and designed to make filing a tax return as straightforward as possible.
Place Your Order
Select the appropriate fixed-fee Self Assessment service.
Secure Onboarding
Complete our engagement and identity verification process.
Send Your Records
Upload the information needed to prepare your return securely.
Review & Approve
We calculate your tax and send the completed return to you for approval.
Filed with HMRC
Once approved, we submit the tax return electronically and confirm filing.
Why Use an Accountant to File Your Self Assessment?
You can prepare a Self Assessment tax return yourself, but the challenge is often not physically submitting the return. It is determining what should be reported, which expenses and reliefs are allowable, which supplementary pages are required and whether the resulting tax calculation is reasonable.
This becomes particularly important when a return includes several sources of income, property, dividends, self-employment, capital gains or overseas income.
Accuracy
Your figures are reviewed before the return is prepared and submitted to HMRC.
Tax Review
We consider relevant allowable expenses, deductions and tax reliefs when preparing the return.
Less Administration
Instead of working through tax forms yourself, you provide the records and we prepare the return.
What Are Self Assessment Payments on Account?
A Self Assessment bill can sometimes be higher than expected because it may include both a balancing payment for the tax year just completed and a payment on account towards the following year's tax liability.
Where payments on account apply, they are normally paid in two instalments, with the first due on 31 January and the second on 31 July. The amount required depends on your tax position and the relevant HMRC rules.
Self Assessment and Making Tax Digital for Income Tax
Making Tax Digital for Income Tax is changing how some sole traders and landlords keep records and report information to HMRC. Depending on your qualifying income and the tax year concerned, you may need to use compatible software and meet additional digital reporting requirements.
This does not mean everyone filing a Self Assessment tax return immediately moves into Making Tax Digital. The rules are being introduced according to HMRC's timetable and eligibility criteria.
If you have self-employment or property income, it is increasingly important to consider whether Making Tax Digital affects you as well as your normal annual tax return obligations.
File Self Assessment Tax Return FAQs
Can an accountant file my Self Assessment tax return for me?
Yes. An accountant can prepare your Self Assessment tax return, calculate the tax due and submit the return electronically to HMRC as your authorised agent. We send the completed return to you for approval before filing.
How much does it cost to file a Self Assessment tax return?
Our fixed-price Self Assessment filing service currently starts at £299 + VAT for income and capital gains up to £30,000. Our medium service is £499 + VAT up to £100,000 and our large service is £699 + VAT up to £250,000. Particularly complex cases may require a separate quotation.
What is the deadline to file a 2025/26 Self Assessment tax return online?
For most taxpayers, the normal deadline for filing the 2025/26 Self Assessment tax return online is 31 January 2027. The normal paper filing deadline is 31 October 2026.
Can I file my Self Assessment tax return before January?
Yes. You do not need to wait until January. The 2025/26 tax year ended on 5 April 2026 and returns can normally be filed from 6 April 2026. Filing earlier can give you more time to plan for any tax payment due.
Do company directors have to file a Self Assessment tax return?
Not simply because they are directors. A director may need to file where their wider tax circumstances require Self Assessment, for example because of untaxed income, dividends, capital gains or other reportable income, or where HMRC has issued a notice requiring a return.
Do landlords need to file a Self Assessment tax return?
Rental income can create a requirement to notify HMRC and complete Self Assessment. Whether a return is required depends on the amount of income and your individual circumstances.
Can you include Capital Gains Tax in my Self Assessment?
Yes, where appropriate. We can calculate and report relevant capital gains as part of your Self Assessment return. Some disposals can also have separate reporting requirements or deadlines, so contact us if you are unsure.
Can you file a late Self Assessment tax return?
Yes, in many circumstances an outstanding return can still be prepared and submitted after the normal deadline. Penalties and interest may already apply, so dealing with an overdue return promptly is generally advisable.
How long does it take to prepare my tax return?
Our average turnaround is normally 7–14 days once we have received the information required to prepare your return. More complex returns can take longer.
Do I need to visit your office?
No. The Online Accountants provides an online Self Assessment service to clients throughout the UK. Documents and information can be supplied securely without visiting an accountant's office.
Will I know how much tax I owe before you file the return?
Yes. We prepare the return and calculate your tax liability before filing. You receive the return for review and approval before it is submitted electronically to HMRC.
What happens after my Self Assessment tax return is filed?
We confirm submission and explain the tax liability shown by the return. You then need to ensure any tax due is paid to HMRC by the applicable payment deadline.
Ready to File Your Self Assessment Tax Return?
Send us your information and let an experienced UK accountant prepare, calculate and file your Self Assessment tax return directly with HMRC.
Fixed fees • Secure online process • UK-wide service • Return sent to you for approval before filing