Tax
Self Assessment tax returns in London
Personal tax returns prepared and filed with HMRC accurately and on time.
What is it
What is Self Assessment?
Self Assessment is the system HMRC uses to collect Income Tax from people whose tax is not fully taken at source through PAYE. After each tax year ends on 5 April, you report your income and gains on a tax return and pay any tax you owe.
Key dates for the 2025/26 tax year
- 5 October 2026: register for Self Assessment if you are filing for the first time.
- 31 October 2026: deadline for paper tax returns.
- 31 January 2027: deadline for online returns and for paying the tax you owe, plus your first payment on account for 2026/27.
- 31 July 2027: second payment on account for 2026/27.
A late return costs £100 straight away, then £10 a day after three months (up to £900), with further penalties after six and twelve months. Late payment adds 5% penalties and interest.
Who we help
Who needs to file a Self Assessment tax return?
You usually need a tax return if you are self-employed with over £1,000 of income, a partner or a landlord, or have untaxed income above your allowances, taxable capital gains or the High Income Child Benefit Charge to pay.
Self-employed and sole traders
Income and expenses reported accurately, ready for Making Tax Digital.
Landlords
UK and overseas rental income, costs and finance cost relief reported correctly.
Company directors and investors
Dividends, interest and gains reported with all allowances applied.
High earners and international clients
Child Benefit Charge, pension relief, Gift Aid and foreign income handled correctly.
What’s included
What our Self Assessment service includes
Tax return preparation
Your full Self Assessment return prepared from your records, with every source of income included.
Online filing with HMRC
Your return filed online well before the 31 January deadline, with confirmation of submission.
Tax calculation and payments on account
A clear breakdown of what you owe and when, including payments on account and, where appropriate, claims to reduce them.
Reliefs and allowable expenses
Pension contributions, Gift Aid, allowable expenses and other reliefs claimed so you pay no more tax than necessary.
HMRC letters and enquiries
We deal with HMRC on your behalf if they have questions about your return or open an enquiry.
How it works
What happens, step by step
- 1
You send us your income details
Employment, self-employment, property, investments and anything else for the tax year.
- 2
We prepare your tax return
We work out your income, allowances and reliefs and calculate the tax.
- 3
You review and approve it
You confirm the return is correct before it is filed.
- 4
We file it with HMRC
And tell you what to pay and when.
What we need from you
- Your Unique Taxpayer Reference (UTR)
- P60, P45 or P11D from your employer
- Self-employment income and expenses
- Rental income and expenses
- Dividend and interest statements
- Pension contributions and Gift Aid donations
- Details of any capital gains
Services
Related services
Corporation tax
Accurate calculation and filing of corporation tax.
Capital gains tax
Advice and preparation for capital gains tax.
Tax consultancy
Strategic tax planning and optimisation.
FAQ
Self Assessment: frequently asked questions
When is the Self Assessment deadline?
For the 2025/26 tax year, online returns and any tax owed are due by 31 January 2027. Paper returns are due by 31 October 2026. If you are filing for the first time, you need to register with HMRC by 5 October 2026.
Do I need to file a tax return if I am employed?
Not usually, if all your income is taxed through PAYE. You may still need to file if you have other income, such as rent, self-employment, dividends or foreign income, or if you have to pay the High Income Child Benefit Charge.
What are payments on account?
If your Self Assessment bill is more than £1,000 and less than 80% of your tax is collected at source, HMRC asks for two advance payments towards next year’s bill, due on 31 January and 31 July. Each is normally half of the previous year’s bill.
What happens if I miss the deadline?
There is an automatic £100 penalty, even if you owe no tax. After three months you are charged £10 a day for up to 90 days, and further penalties apply after six and twelve months. Late payment adds penalties of 5% and interest.
How will Making Tax Digital affect my tax return?
Sole traders and landlords with qualifying income over £50,000 have had to use Making Tax Digital for Income Tax since 6 April 2026, with the threshold falling to £30,000 from April 2027 and £20,000 from April 2028. We can check whether it applies to you and manage your quarterly updates.
Licenses & certificates
