Self Assessment tax returns in London

Who needs to file a Self Assessment return

You usually need to file a Self Assessment tax return if you work for yourself, rent out property, or have income that is not taxed through a payslip. Company directors who take dividends often need one too, because dividend tax is worked out through the return rather than at source.

We prepare the return and file it with HMRC on your behalf, so you do not have to work through the forms yourself. There are some small exceptions to who needs one. If your self-employed income for the tax year is £1,000 or less, the trading allowance may mean you do not need to register at all. The property allowance works the same way for rental income of £1,000 or less. Above those amounts, you need to register with HMRC by 5 October after the end of the tax year you are filing for.

Who it's forSole traders and freelancers, landlords with rental income, company directors with dividends, and anyone whose tax is not fully dealt with through their wages. If you are not sure whether you need to file, the free call is a good place to find out.

How the work runs through the year

Most people think of Self Assessment as a January job. It goes far more smoothly when the work is spread across the year, so questions come up while you still remember the answers.

1. 1

   After 5 April

   The tax year ends and we agree a short list of what we need from you.

2. 2

   Summer

   We gather your records, work through income and costs, and ask any questions early.

3. 3

   Autumn

   We prepare the return and send you the figures, with a note of the tax due.

4. 4

   Before 31 January

   Once you approve the figures, we file with HMRC and confirm what to pay and when.

If we already keep your books through our bookkeeping service, most of the figures are in place before the tax year has even finished. Company directors may also need year-end accounts and Corporation Tax for the company itself, and it helps to plan the two together.

What we need from you

You will also need to authorise us to act for you with HMRC. We send you the request and explain each step, so you never need to share your own HMRC sign-in details with anyone.

What you get back

• A completed return, sent to you to check before it is filed
• A plain-English summary of your income, allowable expenses and the tax due
• Your payment dates, including any payments on account due on 31 January and 31 July
• Confirmation once HMRC has received the return

Payments on account catch a lot of people out. They are advance payments towards next year's bill, so your first January payment can be larger than you expect. We show you the amounts and dates in advance, so the money can be set aside.

Deadlines and penalties

If the deadline has already passed, our guide on what to do after a missed Self Assessment deadline sets out the next steps. Landlords can read more on our accountant for landlords page, and freelancers on our accountant for freelancers page.

Making Tax Digital for Income Tax

From 6 April 2026, sole traders and landlords with qualifying income over £50,000 have to follow Making Tax Digital for Income Tax. That means keeping digital records, sending quarterly updates through compatible software, and then making a final declaration. Qualifying income is gross income from self-employment and property added together. The threshold falls to £30,000 from April 2027 and to £20,000 from April 2028.

Questions people ask