Accounting

Accounts & tax returns

Self Assessment tax returns

Self Assessment is the system HMRC uses to collect income tax that is not taken at source. Employees paid through PAYE rarely need it, but anyone who is self-employed, receives rental income, draws dividends from their own company, earns over £100,000 or has gains to report must file a return each year and pay what is due by 31 January following the tax year. The return itself is the SA100, and almost everyone also needs one or more supplementary pages: SA103 for self-employment, SA105 for UK property, SA108 for capital gains, SA106 for foreign income and so on. Getting the right pages, in the right order, with figures that reconcile to the records HMRC already holds is most of the job.

from £129 · fixed, one-off

Next deadlines

  • Online Self Assessment filing deadline and balancing payment due
  • Second payment on account due
  • Register for Self Assessment if you started self-employment or new untaxed income in the last tax year
  • Paper Self Assessment return deadline

Fees

Packages, fixed and published

£129

Straightforward return — one income source

£169

With rental property income

£199

With capital gains (property, shares, crypto)

£179

Late-return rescue — filed fast, penalties appealed where possible

Who this is for

Self Assessment Tax Returns

Anyone in the UK who has been told to file a return: the self-employed, landlords with one or several properties, company directors taking dividends, people earning over £100,000 or repaying Child Benefit through the High Income charge, and those with capital gains, foreign income or untaxed savings interest to report.

What is included

Inside the fixed fee

  • SA100 and every supplementary page you need (self-employment, UK property, dividends, capital gains, foreign income)
  • A reconciliation against your HMRC personal tax account so nothing is missed or double counted
  • Payments on account calculated and a one-page payment schedule sent to you
  • Claims for allowable expenses, pension relief, Gift Aid and the trading allowance checked before filing
  • Reminders at 60, 30 and 7 days before the 31 January deadline
  • HMRC correspondence about the return we filed handled at no extra charge

In detail

How self assessment tax returns works

Our service is built around that reconciliation. Before a draft goes anywhere near you we pull what HMRC holds in your personal tax account, including employment income, pension income, benefits in kind and any payments on account already made, and match it to the records you send. Discrepancies are the single biggest cause of HMRC enquiries into straightforward returns, and almost all of them are avoidable. The draft you receive shows every figure with its source, the tax computation in plain English, and the payment schedule for the year ahead, including payments on account where they apply.

The fee is fixed by complexity, not by time, and the four packages cover the overwhelming majority of returns. A single income source is £129. Adding UK rental property is £169, because the property pages bring the finance-cost restriction, the property allowance and the question of jointly owned income into play. Capital gains, whether from property, shares or crypto assets, take the return to £199, since each disposal needs its own computation and the reporting rules differ by asset type. Late returns are £179 and include a reasonable-excuse appeal where the facts support one. We tell you which package applies at the quote stage, in writing, and the figure does not change afterwards.

Deadlines are the heart of how we work. HMRC's penalty regime is automatic: £100 the day after 31 January, £10 a day from three months late up to £900, then 5% of the tax or £300 at six and twelve months, plus interest and late-payment penalties on the tax itself. None of this is negotiable after the fact except through a reasonable-excuse appeal, which HMRC applies narrowly. So we send reminders at 60, 30 and 7 days before the deadline, prioritise January work by risk, and never leave a return we have drafted unfiled while we wait for a signature without telling you exactly what is outstanding.

The process is entirely online and works the same in every part of the United Kingdom. You send records by WhatsApp or email; most people photograph receipts and forward PDF statements. We confirm what we have and what is missing within two working days. The draft follows, you approve it, the fee is settled, and we file. HMRC's acknowledgement arrives within minutes and we forward it with the return, the computation and the payment details. If HMRC writes about the return later, we deal with the correspondence at no extra charge. Scottish and Welsh rates, the High Income Child Benefit charge, the personal allowance taper above £100,000, pension annual allowance charges and student loan repayments through Self Assessment are all handled as standard.

Process

From first message to filed

  1. Tell us your situation

    A short message or call about what you do and what needs filing. We ask the questions that determine the right package and nothing more.

  2. Fixed fee in writing

    You receive one price for the work, confirmed by email before anything starts. It does not change if the job takes longer than we expected.

  3. Send records, review the draft

    Records come by WhatsApp or email. We prepare the draft, explain the figures in plain English and answer your questions.

  4. We file, you get the receipts

    Once you approve and the fee is settled, we submit electronically and forward the HMRC or Companies House acknowledgement the same day.

Worth knowing

Rules that come up in this work

Switching accountants

The main reasons people switch accountant are surprise invoices, missed deadlines and not understanding what they are being told. Switching involves a clearance letter between the firms, a transfer of records and agent authorisations, and a short handover of the current position. It takes about two weeks and should cost nothing extra.

Closing a company

A solvent company that has finished its purpose can be dissolved by voluntary strike-off: form DS01 with a £13 Companies House fee, after three months without trading and with all debts paid, final accounts and tax return filed, and assets distributed. HMRC objects to any application where returns or tax are outstanding, so the sequence matters more than the form.

Crypto records and reporting

Most crypto holders have taxable events they do not recognise, because every swap is a disposal even when no pounds change hands. The computation requires the complete transaction history from every exchange and wallet, pooled by asset with HMRC's matching rules applied. Exchange-generated tax reports are frequently wrong because they cannot see transfers between a user's own wallets.

The 60-day property CGT return

Selling UK residential property that was not your main home for the whole period of ownership triggers a separate Capital Gains Tax return, due within 60 days of completion along with payment of the tax. This is in addition to the annual Self Assessment. The gain is taxed at 18% or 24% depending on your income band, after the £3,000 annual exempt amount.

Record keeping

HMRC requires records of all income and expenses, bank statements, invoices and receipts to be kept for at least five years after the 31 January filing deadline of the tax year they relate to, and companies must keep records for six years from the end of the accounting period. Digital copies are acceptable. Under Making Tax Digital the records must be kept in compatible software.

Allowable expenses

Expense claims are where a return is won or lost in an enquiry. The test is wholly and exclusively for the trade; where a cost is mixed, the business proportion can be claimed if it can be identified. Capital items such as equipment and vans are relieved through capital allowances rather than as expenses, except under the cash basis where they are simply deducted when paid.

Employer National Insurance

Since April 2025 employer National Insurance has been 15% on earnings above a £5,000 secondary threshold, a substantial increase for small employers. The Employment Allowance rose to £10,500 at the same time to soften it for the smallest businesses. Directors deciding their own salary weigh this cost against the Corporation Tax deduction a salary provides.

Questions

Self Assessment Tax Returns: your questions answered

What does the £129 return cover?

A full SA100 with the supplementary pages for one income source, prepared, checked and filed online. Rental income, capital gains or several income sources move you to the £169 or £199 package, and we tell you which applies before we start, never on the invoice.

How quickly can you file once I send my records?

Most straightforward returns are drafted within five working days of receiving complete records and filed the day you approve. In January we prioritise by deadline risk and tell you your slot when you book, so late bookers are not left guessing.

I have never filed before. Do I need a UTR first?

Yes. If you have not registered we handle the registration as part of the job and HMRC posts your Unique Taxpayer Reference within about ten working days. Start early if your first deadline is close, because HMRC will not accept a return without it.

What if my return is late?

We file late returns at the £179 rescue fee, which includes drafting a reasonable-excuse appeal where the facts support one. The £100 automatic penalty is HMRC's, not ours, and we tell you honestly whether an appeal has a realistic chance before you pay for it.

Can you deal with HMRC on my behalf?

Once you authorise us as your agent we can speak to HMRC about your return, see your account and respond to letters about the return we filed. The authorisation is free, done through your Government Gateway or a code HMRC posts to you, and takes a few days to activate.

Do I pay before or after filing?

The fee is invoiced when you approve the draft, before we file. Nothing is submitted to HMRC until it is paid and you have confirmed every figure, and you receive HMRC's submission receipt within minutes of filing.

How do payments on account work?

If your bill is over £1,000 and less than 80% of your tax is collected at source, HMRC asks for two advance payments towards next year, due 31 January and 31 July, each half of this year's bill. We calculate both and show you how to reduce them if your income is falling.

Which expenses can I claim as a sole trader?

Costs that are wholly and exclusively for the business: materials, business travel other than ordinary commuting, a proportion of home running costs, software, insurance, professional fees and bank charges. If your expenses are under £1,000 the trading allowance may be better, and we check both.

Do you handle Scottish or Welsh income tax?

Yes. Scottish taxpayers have six bands from 19% to 48% and Welsh taxpayers have Welsh rates set by the Senedd, both applied automatically from the residence HMRC holds for you. We check that address is right, because an out-of-date one is a common cause of wrong tax codes.

What records should I keep, and for how long?

Invoices, bank statements, receipts, P60s and P45s, dividend vouchers and any HMRC letters. Keep them for at least five years after the 31 January filing deadline of the tax year they relate to. Photos and PDFs are acceptable to HMRC; paper is not required.

Will Making Tax Digital change my return?

From April 2026 sole traders and landlords with qualifying income over £50,000 send quarterly updates to HMRC through software, with the £30,000 threshold following in April 2027. The year-end return becomes a final declaration. We set this up through our bookkeeping service when it applies to you.

What happens after you file?

You receive HMRC's submission receipt, a PDF of the return, the tax computation and a payment schedule with HMRC's bank details and your payment reference. We diarise next year's deadlines for you and send reminders before each one.

I am employed and have a small side income. Do I need a return?

If the side income is under £1,000 a year the trading allowance covers it and no return is needed. Above that you must register and file. If the side income is the only reason for the return, the £129 package applies and we make sure your PAYE figures from the P60 are reconciled correctly.

Where

Self Assessment Tax Returns across the UK

This service has a local page for every one of the 60,946 places we cover. A selection:

England: Central London · East London · East Midlands · East of England · M25 Fringe · North East · North East London · North London · North West · North West London · South East · South East London · South London · South West · South West London · West London · West Midlands · Yorkshire

Scotland: Scotland

Wales: Wales

Northern Ireland: Northern Ireland

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Get self assessment tax returns for a fixed fee

Tell us what you need. You get one fixed fee in writing, and nothing is filed until you approve it.

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