---
title: "Self Assessment Registration and Filing Timeline: 2026/27"
description: The 2026/27 Self Assessment process runs beyond the tax year itself. Income arises between 6 April 2026 and 5 April 2027, new taxpayers normally notify HMRC by 5 October 2027, paper returns are due by 31 October 2027, and online…
url: "https://www.accountingfirms.co.uk/knowledge-bank/when-do-i-need-to-do-a-tax-return/"
updated: "2026-08-12"
category: Self Assessment basics
---

# Self Assessment Registration and Filing Timeline: 2026/27

The 2026/27 Self Assessment process runs beyond the tax year itself. Income arises between 6 April 2026 and 5 April 2027, new taxpayers normally notify HMRC by 5 October 2027, paper returns are due by 31 October 2027, and online returns and balancing tax are due by 31 January 2028.

This timeline explains what to do and when. For the separate eligibility question, see our guide to [who must file a Self Assessment return](https://www.accountingfirms.co.uk/knowledge-bank/do-i-need-to-do-a-tax-return/).

## 2026/27 Self Assessment timeline

| Date | Action |
| --- | --- |
| 6 April 2026 | 2026/27 tax year begins; start keeping complete income and expense records |
| 31 July 2026 | Second payment on account for 2025/26, where applicable |
| 5 April 2027 | 2026/27 tax year ends |
| 5 October 2027 | Normal deadline to notify HMRC if newly chargeable and not already registered |
| 31 October 2027 | Paper return deadline |
| 30 December 2027 | Online filing target if eligible tax is to be collected through a PAYE code |
| 31 January 2028 | Online return, balancing payment and first 2027/28 payment on account due |
| 31 July 2028 | Second 2027/28 payment on account due, where applicable |

## Step 1: decide whether you need to notify HMRC

You may need Self Assessment for self-employment, property income, untaxed foreign income, capital gains, partnership income, the High Income Child Benefit Charge or another statutory reason. The old automatic filing requirement for every director and the former £100,000 PAYE-income criterion should not be treated as current standalone rules.

If HMRC sends a notice to file, submit a return or ask HMRC to withdraw the notice where you genuinely do not meet the criteria. Ignoring it can generate penalties.

## Step 2: register by 5 October where required

A person newly chargeable for 2026/27 normally tells HMRC by 5 October 2027. Registration routes differ for self-employment, partnerships and other reasons. You may receive a Unique Taxpayer Reference by post or in your online account.

The 5 October date is a notification deadline, not the return-filing deadline. Register early because identity checks and account activation can take time.

## Step 3: assemble the records

- P60, P45, P11D and employment benefits;
- self-employment sales, costs and capital purchases;
- rental statements, expenses and finance costs;
- bank interest, dividends and investment reports;
- pension contributions and Gift Aid;
- cryptoasset and other capital-disposal calculations;
- foreign income, tax paid abroad and residence information;
- student-loan, Child Benefit and pension details.

Do not wait for January to discover missing platform histories or foreign statements.

## Paper versus online filing

A paper 2026/27 return is normally due by 31 October 2027. An online return is due by 31 January 2028. Some taxpayers and return types cannot use HMRC’s standard online service and need commercial software or a paper route. Filing on paper after the paper deadline while assuming the online deadline applies can trigger a penalty.

## PAYE coding deadline

HMRC may collect a qualifying Self Assessment amount through a PAYE tax code if the return is filed online by 30 December, the amount and income meet HMRC conditions, and the taxpayer has sufficient PAYE income. This is not guaranteed and does not extend the statutory filing deadline.

## Tax payment on 31 January

The January payment can include:

- the 2026/27 balancing payment;
- Class 4 National Insurance where applicable;
- Capital Gains Tax included through Self Assessment;
- student-loan or postgraduate-loan amounts;
- the first payment on account for 2027/28.

Payments on account are normally required where relevant Self Assessment tax exceeds £1,000 and less than 80% was collected at source, subject to the rules. They usually equal half the previous year’s qualifying liability each.

## Making Tax Digital taxpayers

From 6 April 2026, qualifying sole traders and landlords with total gross self-employment and property income over £50,000 enter MTD for Income Tax based on the relevant earlier return. They keep digital records and submit quarterly updates, but still complete the final return and pay by the January deadline.

For standard quarterly periods in the first year, update deadlines are 7 August 2026, 7 November 2026, 7 February 2027 and 7 May 2027. Exemptions and calendar-quarter elections can change the workflow.

## If you miss a deadline

Late filing and late payment are separate penalty systems. Filing the return without paying does not prevent payment penalties and interest; paying an estimate without filing does not prevent filing penalties. Submit as soon as possible, pay what you can and contact HMRC about Time to Pay if necessary.

## Practical checklist

1. Confirm whether HMRC expects a return.
2. Register or reactivate access early.
3. Collect third-party records before summer ends.
4. Reconcile income to bank and platform data.
5. Calculate liabilities and payments on account.
6. File well before the relevant paper or online deadline.
7. Use the correct payment reference and allow processing time.
8. Save the submission receipt and tax calculation.

## Official guidance

- [GOV.UK: Self Assessment deadlines](https://www.gov.uk/self-assessment-tax-returns/deadlines)
- [GOV.UK: register for Self Assessment](https://www.gov.uk/register-for-self-assessment)
- [GOV.UK: payments on account](https://www.gov.uk/understand-self-assessment-bill/payments-on-account)
- [HMRC: MTD for Income Tax](https://www.gov.uk/government/collections/making-tax-digital-for-income-tax)

*This 2026/27 timeline is general information; HMRC notices and individual circumstances can create additional deadlines.*