Self Assessment tax returns, prepared and explained

We prepare your Self Assessment tax return from your records, explain the figures to you and file it with HMRC in good time, so you know what you owe and when it is due.

Employees, sole traders and landlords in Liverpool can send us their records online and have each year’s return prepared, explained and filed in good time.

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What we handle

A check of whether you need to file, with first-time registration or reactivation of your Self Assessment record handled for you

Your return prepared from your records: employment, self-employment, partnership, rental, savings, dividend, pension and foreign income

Capital gains and the High Income Child Benefit Charge reported correctly where they apply

Expenses, reliefs and allowances claimed, including tax relief on pension contributions and Gift Aid where it is due

Your tax calculation explained before you approve the return, with the amounts due on 31 January and 31 July set out

Payments on account reviewed, and a reduction requested from HMRC if your tax for the year is expected to be lower

A check of whether your figures bring you into Making Tax Digital for Income Tax, and from which date

Your return filed online as your agent, with HMRC correspondence about it dealt with on your behalf

Key dates for your 2025/26 tax return

The 2025/26 tax year ran from 6 April 2025 to 5 April 2026. If you need to send a return for it and have not sent one before, or did not need to send one for 2024/25, the deadline for telling HMRC is 5 October 2026. If you register after that date, HMRC will set a filing deadline three months from its letter or email, but the tax is still due by 31 January 2027.

The deadline for paper returns is 31 October 2026; after that, a return filed online by 31 January 2027 is still on time. If you owe less than £3,000 and already pay tax through PAYE, filing online by 30 December 2026 can allow HMRC to collect it through your tax code. The balance for 2025/26, and any first payment on account for 2026/27, are due by 31 January 2027, with the second payment on account due by 31 July 2027.

How Making Tax Digital affects your return

Making Tax Digital for Income Tax works within Self Assessment rather than replacing it. If you started using it on 6 April 2026, your 2025/26 return is filed in the usual way, and your 2026/27 return, due by 31 January 2028, is the first submitted through compatible software. Your 2025/26 return also sets the next start date: if it shows qualifying income from self-employment and property of more than £30,000 before expenses, you will usually need to use Making Tax Digital from 6 April 2027.

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Why 3DOM

We prepare each return with the following year in mind, so payments on account, any Making Tax Digital start date and the effect of a change in income are explained alongside the figures. You can work with us entirely online or visit our office on the Wirral, one Merseyrail stop from Liverpool city centre.

FAQ

Common questions

Do I need to send a Self Assessment tax return?

You must if, in the tax year, you were a sole trader earning more than £1,000 before expenses, a partner in a business partnership, had Capital Gains Tax to pay, or had to pay the High Income Child Benefit Charge and do not pay it through PAYE. Untaxed income such as rent, savings interest, dividends or foreign income can also mean you need to file. We can confirm your position.

I am employed and taxed through PAYE. Do I still need to file?

Not because of a high salary alone: HMRC removed the income threshold for people taxed only through PAYE from 2024/25. You may need to file if you have other untaxed income or gains, or if the High Income Child Benefit Charge applies. That charge starts once adjusted net income is over £60,000 and recovers all Child Benefit once it is over £80,000, and employees with no other reason to file can usually pay it through PAYE instead.

What are payments on account?

They are advance payments towards your next tax bill, each usually half of the tax you owed for the previous year, due by 31 January and 31 July. You do not need to make them if last year’s bill was less than £1,000, or if more than 80% of your tax was collected outside Self Assessment. You can ask HMRC to reduce them if you expect a lower bill, but interest is charged if they prove too low.

What happens if my return or payment is late?

A late return brings an initial £100 penalty. After 3 months, £10 a day is added, up to £900, and at 6 and 12 months a further 5% of the tax due or £300, whichever is greater. Tax paid late attracts penalties of 5% of the unpaid amount at 30 days, 6 months and 12 months, plus interest at the Bank of England base rate plus 4%. Different penalties apply from the tax year you start using Making Tax Digital.

What do you need from me to prepare my return?

Usually your P60 or P45 and any P11D, records of self-employed income and expenses, rent and costs for each property, statements of bank interest and dividends, details of pension contributions and Gift Aid, Child Benefit details, and information on anything you sold or gave away. If you keep your business or property records in Xero or Hubdoc and give us access, we can work from them directly, so there is less to send.

★★★★★

"3DOM handle the accounts for two businesses I run. Paul and the team are first class!"

Richard Oxland · Google review, August 2026

Services

Self Assessment tax returns, prepared and explained

What we handle

Key dates for your 2025/26 tax return

How Making Tax Digital affects your return

Common questions

Related services

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