{"id":5129,"date":"2026-01-21T11:37:37","date_gmt":"2026-01-21T11:37:37","guid":{"rendered":"http:\/\/localhost:8080\/?page_id=5129"},"modified":"2026-04-14T10:12:01","modified_gmt":"2026-04-14T10:12:01","slug":"self-assessment-tax-returns","status":"publish","type":"page","link":"https:\/\/staging.qualitycontracts.co.uk\/guides\/self-assessment-tax-returns\/","title":{"rendered":"Self-Assessment Tax Returns"},"content":{"rendered":"\n
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\n The self-assessment tax return<\/strong> system managed by HMRC\n ensures that individuals report and pay Income Tax on earnings\n not automatically taxed through PAYE (Pay As You Earn)<\/strong>.\n For most permanent employees, taxes are deducted at source by employers.\n However, for individuals with income outside of standard employment,\n such as self-employed professionals, self-assessment is necessary to\n declare their income and calculate any tax owed.\n <\/p>\n <\/div>\n <\/div>\n\n \n

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What is a self-assessment tax return?<\/h3>\n\n

\n A self-assessment tax return provides HMRC with detailed information about\n your income, its sources, and applicable deductions or allowances.\n Taxpayers must ensure their return accurately reflects all taxable income,\n as well as any reliefs or expenses that can reduce their tax liability.\n The tax year runs from 6 April of one year to 5 April of the next, and\n returns, along with any tax owed, are generally due by 31 January\n following the tax year’s end.\n <\/p>\n <\/section>\n\n \n

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Who needs to file a return?<\/h3>\n\n

\n Most people do not need to file a self-assessment tax return, especially\n if they work full-time and their only income is a salary taxed through\n PAYE. A return is usually required if you are self-employed and earn more\n than the \u00a31,000 trading allowance, if you are a company director receiving\n income not taxed under PAYE, or if you are part of a business partnership.\n <\/p>\n\n

\n You must also file if you have foreign income, are a non-resident with\n taxable UK income,are a high earner, or receive rental income above the\n property allowance. A return may be necessary if you or your partner earn\n more than \u00a350,000 while claiming Child Benefit, if you want to claim\n employment expenses above \u00a32,500, or if you have untaxed savings income.\n <\/p>\n\n

\n You must also report profits from selling property, shares, or other\n assets if these create a Capital Gains Tax liability. If you are unsure\n whether you need to file, HMRC provides an\n online tool<\/a>,\n and a qualified accountant can offer further guidance.\n <\/p>\n\n

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\n If you are employed full-time and your only source of income is your\n salary, which is taxed under PAYE, it is unlikely you will need to\n submit one.\n <\/p>\n <\/div>\n <\/section>\n\n \n

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Contractors and self-assessments<\/h3>\n\n

\n Contractors and freelance professionals often have additional tax\n considerations. If you work as a contractor Outside IR35, your income\n likely comes from a combination of salary and dividends. In this case,\n self-assessment is necessary to declare your income and calculate the tax\n due.\n <\/p>\n\n

\n For contractors working Inside IR35, it’s slightly more complicated as\n your income is usually taxed at source via PAYE. If you have additional\n sources of income or meet any of the other criteria above, then you’ll\n have to file a self-assessment. However, if your income is below the\n \u00a3150,000 threshold, you have no other sources of income, and have been\n taxed entirely at source, you do not need to file.\n <\/p>\n\n

\n Even if your income is above the \u00a3150,000 threshold, you may not legally\n be obligated to file a tax return (see below for more detail).\n <\/p>\n <\/section>\n\n \n

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What is a ‘notice to file’?<\/h3>\n\n

\n In some cases, HMRC issues a “Notice to File,” informing you of your\n obligation to submit a tax return. A notice to file is as it sounds,\n someone from HMRC (known as a ‘board officer’) sends you a notice\n informing you that you need to file a self-assessment tax return for that\n year.\n <\/p>\n\n

\n This could be via letter, or it could be via email, depending on if (and\n how) you’ve previously filed in the past. The deadline to file is provided\n in the notice, and complying is mandatory. If you don’t then you may be\n subject to fines and penalties.\n <\/p>\n\n

\n In most situations, if you meet the criteria to file a self-assessment tax\n return and HMRC haven’t sent you a notice to file, then you have a legal\n obligation to notify HMRC of your liability to tax. This is confirmed in\n paragraph SALF210 of the Revenue manuals where it says:\n “Any person who has not been required to complete a tax return, but who\n nonetheless has profits or chargeable gains on which tax is due must\n notify an officer of the board that they are chargeable to tax”<\/i\n >.\n <\/p>\n\n

\n For example, you have a new source of income, or your property income\n breached the threshold for the first time. Notification is done by\n registering for self-assessment.\n <\/p>\n\n

\n If you do not do so by the relevant deadline (by 05 October following the\n end of the tax year on 05th April), you may be charged a ‘failure to\n notify’ penalty. This penalty is calculated as a percentage of potential\n lost revenue.\n <\/p>\n\n

\n There is a specific exemption to the above, captured by TMA 1970, s 7(7)\n that says a person does not need to notify HMRC of their chargeability to\n Income Tax if:\n “all income from it for that year is [income on which] he could not\n become liable to tax under a self-assessment made under section 9 of\n this Act in respect of that year”<\/i\n >.\n <\/p>\n\n

\n This means that if a person submitted a self-assessment tax return, and no\n tax would be due, then they are not required to notify HMRC of their\n chargeability. Furthermore, failure to notify penalties are based on the\n potential lost tax revenue. Since no tax is due, penalties would be nil.\n Given that HMRC has not sent a notice to file, late penalty notices would\n not apply either.\n <\/p>\n\n

\n However, there may be an issue if you think there is no tax owed, but HMRC\n do not agree (e.g you have incorrectly deducted expenses from your income\n that are not allowable).\n <\/p>\n\n

\n In certain circumstances (say you earn over \u00a3150,000 but don’t think you\n owe any tax), you may decide it’s better to be safe than sorry and file a\n tax return anyway.\n <\/p>\n\n

\n It is also important to stress again that if HMRC have asked you to\n complete a return, you will still need to complete one. Once an individual\n has been issued with a notice to file, they have an obligation to file\n that return. It is not appropriate to ignore it on the basis that they\n believe no liability arises.\n <\/p>\n\n

\n However, it is possible to ask HMRC to withdraw a notice to file after it\n has been issued. This is at HMRC’s discretion, although it is likely to be\n accepted if the taxpayer does not meet the normal criteria for being\n within self-assessment.\n <\/p>\n <\/section>\n\n \n

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How to register for self-assessment?<\/h3>\n\n

\n There are different ways to register for self-assessment, depending\n whether you’re: (i) self-employed as a sole trader, (ii) not self-employed\n as a sole trader, or (iii) a partner or in a partnership.\n <\/p>\n\n

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1. Sole Trader<\/p>\n

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\n HMRC provides detailed guidance on how to register for\n self-assessment as a sole trader\n here<\/a>.\n If you’re self-employed as a sole trader, you need to register for\n both self-assessment and Class 2 National Insurance Contributions.\n <\/p>\n

\n You register via your business tax account, known as\n Government Gateway<\/a\n >. Gateway.\n <\/p>\n

\n If you do not have an account, you’ll be able to create one. You’ll\n get your Unique Taxpayer Reference (UTR) by post in 10 working days\n (21 days if you’re abroad). You should also receive a separate\n letter with an activation code.\n <\/p>\n

\n Once you’ve received your UTR number and activation code, you can\n log in and activate your business tax account. Once you’ve done\n this, you should be able to add self-assessment and Class 2, and\n file your tax return.\n <\/p>\n <\/div>\n <\/div>\n

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\n 2. Note Self-Employed as a Sole Trader\n <\/p>\n

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\n HMRC provides detailed guidance on how to register for\n self-assessment if you’re not self-employed as a sole trader\n here<\/a\n >. Those who are not self-employed as a sole-trader, and are\n required to register for self-assessment, need to do so using form\n SA1<\/a\n >.\n <\/p>\n\n

\n \n If you are a contractor, working Outside IR35 via a limited\n company, or Inside IR35 via an umbrella company, this is likely\n the option you need.\n <\/strong>\n To register and complete the form (even if you decide to print it\n out and post), you’ll need to create a personal tax account via\n Government Gateway. Once you’ve submitted form SA1, you’ll get your\n UTR by post in 10 working days (21 days if you’re abroad). You\n should also receive a separate letter with an activation code.\n <\/p>\n

\n Once you’ve received your UTR number and activation code, you can\n log in and activate your personal tax account. Once you’ve done\n this, you should be able to add self-assessment, and file your tax\n return.\n <\/p>\n <\/div>\n <\/div>\n

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3. Partner or in a Partnership<\/p>\n

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\n HMRC provides detailed guidance on how to register for\n self-assessment if you’re a partner or in a partnership\n here<\/a>.\n If you’re a partner or in a partnership, you need to register for\n both self-assessment and Class 2 National Insurance Contributions\n via form\n SA401<\/a\n >.\n <\/p>\n

\n If you’re the ‘nominated partner’, you must also register your\n partnership using form\n <\/a\n >SA400. You’ll need your partnership’s UTR number to complete form\n SA401. You can complete the form online or print it out and post it\n to HMRC.\n <\/p>\n <\/div>\n <\/div>\n <\/div>\n <\/section>\n\n \n

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Self-assessment deadlines<\/h3>\n\n

\n It’s important to remember that your self-assessment tax return is\n submitted based on the tax year as opposed to the calendar year. The tax\n year runs from 06th April to 05th April the following year.\n <\/p>\n\n \n The 2025\/2026 tax year runs from 06th April 2025 to 05th April 2026. You\n need to:\n <\/strong>\n\n