Do I need an accountant for self assessment?

Self Assessment has a reputation as something everyone eventually has to wrestle with, but in reality a large share of UK taxpayers never need to file a return at all. Whether you fall inside HMRC's Self Assessment system comes down to a specific set of triggers, not simply how much you earn, and it is worth understanding which of them actually apply to you before assuming either that you are exempt or that you need professional help.

HMRC requires a return from anyone who meets any one of several conditions. These commonly include: being self-employed with gross trading income over £1,000 in the tax year; receiving rental income over £1,000 before expenses; receiving dividend income above the dividend allowance; realising capital gains above the annual exempt amount; being liable for the High Income Child Benefit Charge, which applies where you or your partner claims Child Benefit and one of you has adjusted net income over the relevant threshold; or simply because HMRC has sent you a formal notice to file, which must be complied with regardless of how much you actually earned that year. Company directors, ministers of religion, and people with certain foreign income or untaxed savings interest can also be drawn in under separate rules. None of these triggers depend purely on your total income once you strip PAYE earnings out of the picture.

The income-based trigger is the one that has genuinely changed in recent years, and it is worth being precise about it rather than relying on an old rule of thumb. For a long stretch, anyone with total income over £100,000 had to file a return purely because of that income level, even with no other complicating factors. That threshold was later raised to £150,000, and then, from the 2023-24 tax year onward, HMRC went further and removed the income-only trigger altogether for anyone whose sole income is taxed through PAYE. In practice, this means an employee earning £160,000 a year with no self-employment, rental income, dividends or other untaxed income no longer has to file a return simply because of their salary. That change does not extend to anyone with income outside PAYE — self-employment profits, rental income, dividends above the allowance, or meaningful untaxed interest can still bring you into Self Assessment regardless of your total income. Because this rule has moved more than once in a short period, checking your specific position on gov.uk, or with an accountant, is more reliable than assuming a figure you remember from a previous tax year still applies.

If this is the first year you need to report income, registration itself has its own deadline, separate from filing: you must register for Self Assessment by 5 October following the end of the tax year in which the reportable income arose. For income first arising in the 2025-26 tax year, that means registering by 5 October 2026.

Once registered, the filing deadlines are fixed points every year. Paper returns are due by 31 October following the end of the tax year; returns filed online, which is how the large majority of people file, have until 31 January — so a 2025-26 return is due online by 31 January 2027. Missing the online deadline triggers an automatic £100 penalty, even if you owe no tax at all. If a return is still outstanding three months later, HMRC can add daily penalties of £10, up to a maximum of £900 over 90 days. At six months, a further penalty applies — 5% of the tax due, or £300, whichever is greater — and the same again at twelve months. These are filing penalties specifically; separate interest and penalties apply if tax owed is paid late, on top of any filing penalties already charged.

None of this legally requires you to use an accountant. HMRC's own online system is genuinely manageable for straightforward situations — a single PAYE job alongside one rental property, for example, or simple dividend income within otherwise ordinary circumstances. An accountant tends to earn their fee once things get more layered: self-employment with a meaningful list of allowable expenses, multiple income sources that interact with each other, capital gains calculations, or reliefs that are easy to miss if you do not know to look for them, such as pension carry-forward or the Rent-a-Room scheme.

Fees for accountants preparing a standard Self Assessment return commonly sit somewhere between £150 and £400 plus VAT, with straightforward single-income returns toward the lower end and returns involving self-employment, multiple properties, dividends or foreign income pushing toward the upper end or beyond. Ranges vary meaningfully by firm, location and the complexity of your affairs, so it is worth getting more than one quote and confirming exactly what is included before committing.

This article is general information, not tax or accounting advice, and everyone's filing position depends on their own specific circumstances. If you are unsure whether you need to file, or which reliefs might apply to you, checking gov.uk directly or speaking to a qualified accountant is the reliable next step, and our directory lists UK accountants by area if you decide professional help is the right call.

Frequently asked questions