360 Accounts & Bookkeeping Ltd

    Self Assessment Registration Deadline - 5 October 2026

    Tax KnowledgeUpdated 14 October 2026

    Self Assessment registration for 2025/26, what to do if you missed 5th October

    Overview

    If you need a Self Assessment tax return for 2025/26 and are new to the system, or need to reactivate an account, HMRC’s notification deadline was 5th October 2026. This is separate from the deadlines for filing your return and paying tax.

    That date has now passed. If you should have registered but have not done so, act promptly. Missing the notification deadline does not automatically produce a £100 fine, but a failure-to-notify penalty may apply if relevant tax remains unpaid by the normal payment deadline.

    Registration does not submit your return or pay your tax. This guide is general information; your obligations depend on your income, reliefs and circumstances.

    Detailed Content

    Who needs to register?

    For the tax year from 6th April 2025 to 5th April 2026, common reasons for needing a return include:

    • Self-employment as a sole trader with gross trading income above £1,000, before expenses, subject to the applicable rules and exceptions.

    • Being a partner in a business partnership.

    • Rental income that needs to be reported through Self Assessment.

    • Untaxed savings, dividends, overseas income or other income that cannot be dealt with appropriately through another HMRC route.

    • A Capital Gains Tax liability requiring a return.

    • A High Income Child Benefit Charge that is not paid through PAYE.

    Income above £100,000 is not, by itself, an automatic Self Assessment requirement for 2025/26. Someone whose income is fully dealt with through PAYE may not need a return solely because of its amount. Check for other reporting obligations and whether HMRC has issued a notice to file.

    There is no single £2,500 threshold covering every type of untaxed income. For example, HMRC’s guidance says personally owned rental income must be reported on a return if it exceeds £2,500 after allowable expenses or £10,000 before allowable expenses. For rental income above £1,000 and up to £2,500, contact HMRC to establish how it should be reported. Allowances, exemptions and different income types can change the answer.

    Use HMRC’s Self Assessment checker rather than relying on one income figure. If HMRC has asked you to file, meet that obligation unless HMRC confirms the notice has been withdrawn. Some capital gains also have separate reporting and payment deadlines, so do not assume all gains can wait until January.

    How to register or reactivate an account

    Start with HMRC’s official registration service and select the route matching your circumstances.

    If you registered previously but did not need a return for 2024/25, you may need to reactivate your account. Continuing Self Assessment taxpayers do not normally register again each year. Do not apply for a duplicate Unique Taxpayer Reference (UTR) simply because you have misplaced the original.

    Provide accurate identity, address and contact details, and retain the confirmation. HMRC’s own registration service is free. Paying an accountant for advice or assistance is different from paying an unnecessary fee to access an official service.

    Receiving your UTR

    HMRC announced an improved registration service in September 2026. Individuals using the new service through their Personal Tax Account are expected to receive their UTR in their online account within 72 hours, rather than waiting for a postal letter.

    This is HMRC’s published service expectation, not a guarantee for every application. Other registration routes may have different processing times. Check HMRC’s current response-time guidance if you are waiting, and ensure your contact details are correct.

    Agents must continue using HMRC’s applicable agent registration processes; the new individual service is not an agent-registration route. Keep your UTR and sign-in details secure, and never share your password with an adviser.

    What happens if you missed 5th October?

    Yes, the notification deadline has passed, but you should still register or reactivate promptly if required.

    HMRC’s current guidance says that if you register after 5th October 2026, it will send a letter or email giving a filing deadline three months from the date of that communication. Check the actual deadline HMRC issues.

    That later filing deadline does not extend the normal payment deadline of 31st January 2027. You may need to estimate the amount due and arrange payment before your return is completed.

    Failure-to-notify penalties are separate from late-filing penalties. HMRC says a failure-to-notify penalty may apply where you register late and do not pay all the relevant tax by 31st January. Paying the relevant liability in full by that date will normally leave no tax-based failure-to-notify penalty for an ordinary late-notification case. Individual circumstances, reasonable excuses and statutory exceptions need checking.

    Filing and payment dates

    For an ordinary individual 2025/26 return, the normal dates are:

    • 5th October 2026: notification or registration deadline, where required.

    • 31st October 2026: HMRC must receive a paper return.

    • 30th December 2026: online filing deadline if you want an eligible bill collected through your PAYE tax code.

    • 31st January 2027: online filing deadline and normal deadline for the balancing payment, plus the first payment on account where applicable.

    • 31st July 2027: second payment on account, where applicable.

    A separately issued filing deadline can apply, including following late registration. Check HMRC’s notice rather than assuming a standard date always applies. Special return types can also have different arrangements.

    Penalties and interest

    Under the ordinary Self Assessment rules, filing after your applicable deadline normally triggers an initial £100 penalty, even if no tax is due. Further late-filing penalties can follow after three, six and twelve months.

    Late payment normally attracts interest, with additional penalties at the relevant stages. A later filing deadline is not permission to pay late. Contact HMRC before the payment deadline if you need to discuss an affordable payment arrangement.

    Step By Step Procedure

    1. Identify all income and relevant disposals for 6th April 2025 to 5th April 2026, including trading, property, savings, dividends and overseas income.

    2. Check HMRC’s return checker, relevant income-specific guidance and any notice to file.

    3. If required, register or reactivate promptly through the correct HMRC route. If you already have an active account, check your existing filing obligations instead.

    4. Retain the confirmation and monitor your online account and correspondence for the UTR and filing deadline.

    5. Gather records, arrange online filing access or appoint an authorised adviser, and prepare the return.

    6. Budget for payment by 31st January 2027, including payments on account where applicable, even if HMRC gives you a later filing deadline.

    7. Keep proof of submission and payment. If you cannot pay, contact HMRC promptly rather than ignoring the bill.

    360 Accounts & Bookkeeping can help assess whether a return is needed, support registration or reactivation, prepare your return and explain the tax and payment deadlines.

    Frequently Asked Questions and Answers

    Is 5th October the tax return filing deadline?

    No. It is the notification deadline for people who need to enter or reactivate Self Assessment. The usual paper deadline is 31st October 2026 and the usual online deadline is 31st January 2027, subject to any separately issued deadline.

    Have I missed the deadline if I did not register by 5th October 2026?

    Yes, if you were required to notify HMRC by that date. Register promptly. Missing it does not automatically mean a £100 penalty, but late notification and unpaid tax can have consequences.

    I have a PAYE job and a side business. Do I need to register?

    You generally need Self Assessment if your gross sole-trader income exceeds £1,000, subject to the relevant rules. The threshold is based on income before expenses, not profit. PAYE employment does not remove a separate reporting obligation.

    Does earning more than £100,000 automatically mean I need a return?

    No, not for 2025/26 solely because of the amount of PAYE income. Other income, gains, charges, claims or a notice to file can still require a return. Check your full position.

    How long does a UTR take?

    HMRC says individuals using its new Personal Tax Account registration service should receive the UTR online within 72 hours. Other routes and individual cases can take longer. Do not rely on a blanket ten-working-day postal estimate.

    If I register late, do I get longer to pay?

    No. HMRC’s published guidance gives late registrants a filing deadline three months from its letter or email, but the normal payment deadline remains 31st January 2027.

    Can I send a paper return after 31st October?

    Not without potentially being late, unless a different applicable filing deadline has been issued. If you miss the normal paper deadline, you can usually still file online by 31st January 2027. Check whether your return type can be filed online and what deadline applies.

    Does registration mean my return has been submitted?

    No. Registration, filing and payment are separate steps. Keep confirmation of each.

    Does Making Tax Digital remove the need for my 2025/26 return?

    No. Being signed up to Making Tax Digital for Income Tax does not remove an existing obligation to file the 2025/26 Self Assessment return and pay the tax due.

    Related services

    Business Start Up & Formation

    360 Accounts & Bookkeeping Ltd provides business start-up and company formation services for entrepreneurs, sole traders, partnerships and new limited companies in Guildford, Woking and Surrey. We help you make the right decisions from day one, so your business is structured efficiently, registered correctly and ready to trade with confidence. Choosing the right legal structure can affect tax, personal liability, administration and future growth. We take time to understand your business idea, expected income, circumstances and long-term ambitions, then advise whether operating as a sole trader, limited company or partnership is the most suitable option. If a limited company is right for you, we manage the Companies House incorporation process, including company details, share structure, registered office address, memorandum and articles of association. We can also assist with relevant HMRC registrations, including Corporation Tax, PAYE for directors or employees, and VAT registration where required or beneficial. Our business start-up service includes practical initial tax planning and a clear compliance calendar, so you understand filing dates, tax payments and ongoing responsibilities. We explain what is required after formation and help you avoid missed deadlines, penalties and common early-stage mistakes. We can establish strong financial systems from the outset, including cloud accounting software such as QuickBooks or Xero, bookkeeping procedures, business bank-account guidance and invoicing processes. If you plan to employ staff, we can support PAYE registration, payroll and pension auto-enrolment duties. Our support continues after registration, with bookkeeping, accounts, VAT, payroll and tax services from a team that understands your business from its first day. Whether you are leaving employment, launching a side venture or turning an idea into a growing business, we make business formation straightforward, compliant and tailored to your goals.

    View service

    Partnership Accounts

    360 Accounts & Bookkeeping Ltd provides partnership accounting services for businesses across Surrey. We help partnerships maintain accurate financial records, meet HMRC obligations and give every partner confidence in how income, expenses, capital and profits are managed. Partnership accounting has specific requirements. Profits and losses must be allocated correctly under the partnership agreement, while each partner’s capital contributions, drawings and retained profits must be tracked. When a partner joins, leaves or changes their entitlement, there can be significant accounting and tax consequences. We ensure the accounts reflect the commercial arrangement and give partners clear reporting. Our service includes annual partnership accounts, showing income, expenses and profit allocation. We prepare and submit the SA800 partnership tax return to HMRC, and can prepare each partner’s individual Self Assessment return. We ensure each partner’s share is reported consistently with their other income. We manage partner capital accounts, track drawings and contributions, and advise on profit-sharing arrangements. We can review your bookkeeping processes or work with Xero and QuickBooks, helping keep records up to date throughout the year. Clear information supports decisions and reduces misunderstandings. Partnerships must keep accurate business records and meet tax deadlines. Late or incorrect returns can lead to penalties for both the partnership and its partners. Our team keeps the process organised, prepares accounts and returns on time, with clear guidance. Whether you are a new partnership, an established practice or considering a change in structure, we offer practical, responsive support. We can also advise whether a partnership, LLP or limited company remains the most suitable and tax-efficient structure for your business. Contact 360 Accounts & Bookkeeping Ltd for partnership accounts, tax and compliance support.

    View service

    Payroll Services

    360 Accounts & Bookkeeping Ltd provides payroll services for businesses across Surrey. We take the complexity out of paying your employees, ensuring accurate, compliant and timely pay and HMRC submissions. Payroll is subject to strict rules, including PAYE, National Insurance, Real Time Information (RTI) reporting and workplace pension auto-enrolment. Errors and missed deadlines can lead to penalties. By outsourcing your payroll to us, you save administration time and gain confidence that your employer responsibilities are being handled professionally. We process weekly, fortnightly or monthly payrolls, calculating gross pay, PAYE Income Tax, employee and employer National Insurance, pension contributions, student-loan deductions, statutory payments and net pay. We prepare employee payslips and reports showing the amounts due to HMRC and pension providers. Our service includes submitting Full Payment Submissions (FPS) to HMRC on or before payday, and Employer Payment Summaries where required. We also support new starters and leavers, issue P45s, prepare year-end P60s, and can assist with P11D returns for taxable benefits. We manage workplace pension auto-enrolment duties, including assessing eligible employees, calculating contributions, processing opt-ins and opt-outs, communicating with pension providers and supporting re-enrolment requirements. If you are employing staff for the first time, we can help with PAYE registration and payroll setup. We work with businesses of all sizes and can integrate payroll information with accounting software such as Xero, QuickBooks and Sage. Simply provide any changes before each pay run, including overtime, bonuses, absences, starters or leavers, and we will handle the rest. With 360 Accounts & Bookkeeping Ltd, your employees are paid correctly and your payroll compliance remains under control, leaving you more time to run and grow your business.

    View service

    Personal Taxation

    360 Accounts & Bookkeeping Ltd provides personal tax return and Self Assessment services for individuals across Guildford, Woking and Surrey. We prepare accurate HMRC tax returns, identify legitimate tax reliefs and allowances, and help you understand what to pay and when. You may need to file a Self Assessment tax return if you are self-employed, a company director, landlord, higher earner, receive income from investments, savings or overseas sources, have made capital gains, receive trust income, or need to claim certain reliefs. Tax rules, deadlines and payment-on-account requirements can be confusing. Errors or late returns can result in HMRC penalties and interest. We gather and review the information relevant to your circumstances, including P60s, P11Ds, self-employment records, rental accounts, bank interest, investment income, pension contributions, Gift Aid donations and capital-gains details. We prepare your return, check each figure carefully and send it to you for approval before filing online with HMRC. Our personal tax service covers Self Assessment preparation and filing, tax calculation, payment-on-account guidance, tax code reviews, HMRC correspondence and support with new Self Assessment registrations. We provide a clear summary of your tax position and payment dates, helping you budget with confidence. We take a proactive approach to personal tax planning. As well as ensuring compliance, we review available deductions, allowances and reliefs to help minimise the tax you pay within the law. This may include pension tax relief, Gift Aid, ISA planning, Marriage Allowance, work-related expenses and the timing of asset disposals for Capital Gains Tax. We support complex tax affairs, including multiple income sources, rental property, foreign income, investments and capital gains. With 360 Accounts & Bookkeeping Ltd, you receive practical support and confidence that your personal tax return is complete, compliant and submitted on time.

    View service

    Sole Trader Accounts

    360 Accounts & Bookkeeping Ltd provides sole trader accounts and tax support for businesses in Guildford, Woking and across Surrey. We help freelancers, tradespeople, consultants keep accurate records, meet HMRC requirements and reduce tax where legitimate. Every sole trader must keep income and expense records, complete a Self Assessment tax return and pay the correct Income Tax and National Insurance. Our straightforward service removes the burden of accounts and deadlines, leaving you more time to run your business. We prepare annual sole trader accounts that clearly show income, expenses and taxable profit. We complete and submit your Self Assessment tax return to HMRC, ensuring figures are accurate and eligible deductions are claimed. We also advise on allowable expenses, including business travel, use of home, equipment and professional subscriptions. You receive clear tax-payment guidance, including balancing payments and payments on account. Important dates are 5 April, the tax-year end; 31 January, the online filing and main payment deadline; and 31 July, when the second payment on account is normally due. We file in good time to help avoid HMRC penalties. As your business develops, we provide practical advice based on your figures. This may include VAT registration, employing staff, profitability, cash flow and whether trading through a limited company could be appropriate. Incorporation can offer tax and liability advantages, but it also brings extra reporting duties; we explain the options clearly. We support sole traders preparing for Making Tax Digital for Income Tax. MTD starts from April 2026 for qualifying income above £50,000 and from April 2027 for qualifying income above £30,000. We can help with digital records, compatible software and quarterly reporting. With a dedicated accountant and accessible support by phone, online or at our Guildford office, 360 Accounts & Bookkeeping Ltd makes sole trader accounting simple, compliant and useful.

    View service

    Related resources

    Still have questions?

    Talk to our team of accountants and bookkeepers — we'll give you a straight answer.