• You are self employed or in a partnership
• You get dividend income of over £10,000 pa (amounts less than this have to be advised to HMRC by telephone or via your personal tax account)
• You have rental property with gross income of more than £10,000 or net income after expenses of more than £2,500 (you need to tell HMRC if less than £2,500)
• You have a holiday let with gross income of more than £10,000 or net income after expenses of more than £2,500 (you need to tell HMRC if less than £2,500)
• You get foreign income
• You have untaxed income like royalties or commissions
• You need to claim relief on expenses or pension contributions
• You need to declare tax charges if your pension contributions have exceeded the set limits
• Your income is over £50,000 and you or your partner/spouse are claiming child benefit
• You earn over £150,000 including benefits in kind from your employment (anyone with income less than £150,000 will be dealt with by HMRC directly)
• You get interest income of over £10,000 (amounts less than this have to be advised to HMRC by telephone or via your personal tax account)
• You get income from a trust
• You have sold an asset which is subject to capital gains tax (unless it is a residential property and you have already completed a Capital Gains on UK Property  Report in which case no tax return is required to report a capital gain)

Please note that HMRC are increasingly using simple assessments to assess your tax without you needing to do a Tax Return.  If any tax is due they will assess the amount using information provided and give you payment instructions.

HMRC have a tool which you can use to see if you need to submit a Tax Return.  Please go to gov.uk – Check if you need to send a self assessment tax return.