What are the requirements to complete a self-assessment return?
Answered 17 March 2026
Requirements to Complete a Self-Assessment Return
What the law says
The legal framework for Self Assessment is contained in the Taxes Management Act 1970 (TMA 1970). The key provisions are:
- Section 8 TMA 1970 governs the personal return, requiring individuals to declare the amounts in which they are chargeable to income tax and capital gains tax for the year of assessment.
- Section 9 TMA 1970 requires that every return under s.8 must include a self-assessment — an assessment of the amounts chargeable to income tax and capital gains tax, and the amount payable by way of income tax (after deducting tax deducted at source and tax credits).
- The obligation to file is triggered by a notice to file issued by HMRC under s.8(1)(a) TMA 1970. Once issued, the taxpayer is required to complete and file the return by the due date, regardless of the level of their income.
- Where no notice to file has been received, section 7 TMA 1970 requires a taxpayer who is chargeable to tax to notify HMRC of their chargeability within the statutory time limit.
- The filing deadline is 31 January of Year 2 (for the tax year ending in Year 1), or if the notice is given after 31 October of Year 2, the last day of the period of three months beginning with the date of the notice.
- A return must be made in the form prescribed by HMRC under section 113 TMA 1970 and must contain the declaration required by section 8(2) TMA 1970 — a letter or informal communication does not constitute a valid return.
HMRC guidance / practice
Who needs to file
HMRC guidance sets out that a Self-Assessment tax return is required if the customer is or was:
- Self-employed
- In receipt of £2,500 or more in untaxed income (e.g. from renting out a property, but not including savings, investment or dividend income)
- In receipt of savings or investment income (excluding dividends) of £10,000 or more before tax
- In receipt of dividend income of £10,000 or more before tax
- Making profits from selling chargeable assets (e.g. shares, a second home) and needing to pay Capital Gains Tax
- A company director (with some exceptions, e.g. unpaid directors of charities)
- In receipt of income (or their partner is) over £50,000 and one of them claimed Child Benefit
- In receipt of income from abroad, or living abroad with UK income
- In receipt of total taxable income of more than £100,000 (for tax years 2017–18 to 2022–23) or £150,000 (2023–24); this criterion does not apply from 2024–25 onwards
- A trustee of a trust or registered pension scheme
- In receipt of a P800 from HMRC showing underpaid tax not collected through the tax code
What must be included in the return
- The return must include all relevant income sources. For example, where there is self-employed income, the self-employment pages must be completed — a return is not capable of being properly made without them.
- Supplementary pages must be used for specific income types (e.g. SA101 for life insurance policy gains from UK policies; SA106 for foreign policy gains).
- SA affects individuals, partnerships and trustees who receive tax returns, as well as non-UK resident companies not trading through a UK permanent establishment, and individuals who do not receive a return but need to claim a relief or allowance.
- Many taxpayers with simple affairs who pay tax through PAYE do not need to file an annual return.
- Where a taxpayer's trading income does not exceed £1,000 (the trading allowance), they will not need to complete a self-assessment return unless they wish to utilise losses or elect for partial relief.
Citation sources
Stanley has employment income from his full time job but also runs a small advertising business in his spare time. Depending on other commitments Stanley can spend varying amounts of time working on the business and year on year his gross income is either just below £1,000 or just above £1,000. Stanley will have to work out his gross income every year to determine whether he needs to complete a self-assessment return. If Stanley’s gross income is: • no more than the £1,000 allowance he will auto
This guide to the legal framework is an up-date of what was 'Self Assessment Technical 2: Self Assessment: the legal framework’, commonly referred to as 'SAT 2'. The original SAT 2 was written in 1994 (and updated in 1995) to introduce the new Self Assessment scheme. Legislation to pave the way for the change, from HMRC assessing taxpayers to a scheme of self assessment, was included in the 1994 Finance Act. The legislation laying down the procedures for income tax Self Assessment (SA) is in Tax
under Schedule 55 FA 2009 and not Schedule 24 Finance Act 2007. Read in the light of the letter of 20 April, it is clear that the letter of 15 April was referring to the penalty charged under Schedule 24 of Finance Act 2007 for the years 2008-09 to 2011-12. It follows that the penalties for 2014-15 remained due and payable. 88. Mr Dublin also submitted that Ms Gill made a return for 2014-15 in the letter of 25 October 2017. We accept HMRC’s submission that the letter was not a valid return as it
The person liable to tax on the gain – see IPTM3200 – should report the gain. The action to take will depend on the individual’s circumstances as follows: 1. If the individual is already within Self Assessment, the gain should be reported in their Self Assessment tax return. 2. If the individual is not within Self Assessment, but the gain (together with their other savings and investment income) exceeds £10,000, they will need to register for Self Assessment and report the gain in their Self A
Part 6 Investigation, administration etc Filing dates Consequential amendments 91 1 In section 9(2) of TMA 1970 (returns to include self-assessment)— a in paragraph (a), for “30th September” substitute “ 31st October ” , and b in paragraph (b), for “31st July” substitute “ 31st August ” . 2 In section 9ZA of TMA 1970 (amendment of personal or trustee return), for subsection (3) substitute— 3 In this section “the filing date”, in respect of a return for a year of assessment (Year 1), means— a 31s
From April 2016, changes in the SA criteria mean that a Self-Assessment tax return will be required if the customer is or was self-employed in receipt of £2,500 or more in untaxed income (but not including savings, investment or dividend income) for example from renting out a property in receipt of savings or investment income, not including dividends, of £10,000 or more before tax in receipt of dividend income of £10,000 or more before tax making profits from selling things like shares, a secon
Where a taxpayer has not received a notice to file under s8 TMA 1970, or where they have received a notice and subsequently had it withdrawn, then s7 TMA 1970 states that they have an obligation to notify HMRC that they are chargeable to tax within the time limit given at s7(1C) TMA 1970. The taxpayer must notify HMRC for each year that they are chargeable. Where the taxpayer has not notified HMRC of chargeability then there is a failure to notify under s7 TMA 1970. Section 36(1A)(b), TMA 1970 o
nalties: the Return was filed the day after the phone calls with HMRC that clarified to Mr Little and the Appellant that HMRC’s position was that it had not been filed; and on the next day a further appeal to HMRC was prepared on the basis that the Appellant had filed the Return on time. The point being that the Appellant or someone helping her generally took action to rectify the situation and/or appeal a penalty once they realised there was an issue and what that issue was. Therefore, we find