HMRC Launches Faster Self Assessment Registration Service: 5 October 2026 Deadline

HMRC has launched an improved online service for people registering for Self Assessment, just weeks before an important tax deadline.

Anyone who needs to submit a 2025/26 Self Assessment tax return for the first time should check whether they need to notify HMRC by 5 October 2026.

The new system is designed to make registration quicker and simpler, with HMRC saying that some taxpayers can now receive their Unique Taxpayer Reference (UTR) in their online account within 72 hours, rather than waiting up to 15 days for it to arrive by post.

For sole traders, landlords, business owners and individuals receiving untaxed income, this is a useful reminder not to leave Self Assessment registration until January.

Key points at a glance

• 5 October 2026 – deadline to notify HMRC if you need to file a 2025/26 Self Assessment return for the first time.
• 31 January 2027 – deadline for submitting the 2025/26 online tax return and paying tax due.
• HMRC’s improved registration system is available through the Personal Tax Account.
• Information can be pre-populated during registration.
• The system includes a save and return function.
• Confirmation can be sent by email or text.
• A UTR may be available online within approximately 72 hours.
• Accountants and tax agents continue to use the existing agent registration processes.

Who may need to register for Self Assessment?

There are many circumstances in which an individual may need to complete a Self Assessment tax return.

HMRC specifically highlights people who are newly self-employed and have gross trading income above £1,000.

Registration may also be required if you have become a new partner in a business partnership or have received certain untaxed income of more than £2,500.

Other circumstances can also create a Self Assessment obligation, so you should not assume that Self Assessment only applies to traditional sole traders.

For example, landlords and individuals receiving additional sources of income should review their position carefully.

What has changed with HMRC’s new registration service?

The improved Self Assessment registration service was launched by HMRC on 9 September 2026.

Previously, obtaining a UTR could involve waiting for correspondence through the post. Under the new process, HMRC says taxpayers using the service can receive their UTR in their online account within around 72 hours.

The new registration journey also includes:

Pre-populated information

Some information HMRC already holds can be automatically entered, reducing the amount taxpayers need to complete manually.

Save and return

You can save the registration and return to it rather than having to complete the entire process in one session.

Digital confirmation

HMRC can provide confirmation by email or text when the registration has been completed.

These changes should make the registration process more convenient, but they do not change the underlying Self Assessment deadlines.

The 5 October 2026 deadline is important

A common mistake is to focus only on the 31 January tax return deadline.

But if you are new to Self Assessment, HMRC first needs to know that you are required to submit a return.

For the 2025/26 tax year, the key notification date is:

5 October 2026

The 2025/26 tax year ran from 6 April 2025 to 5 April 2026.

The deadline for submitting the online return and paying the tax due is then 31 January 2027. HMRC states that registering after 5 October could result in a penalty.

Registering early also gives you more time to obtain your UTR, gather your records and deal with any queries before the January deadline.

Are the rules different if you use an accountant?

There is an important distinction between the new HMRC service for individuals and the procedure used by accountants.

The improved online service is aimed at individual taxpayers using their Personal Tax Account.

HMRC has confirmed that tax agents should continue to use the existing registration procedures, including CWF1 or SA1 where appropriate.

Therefore, businesses and individuals using an accountant should not assume that the new Personal Tax Account registration journey has replaced the agent process.

What should you do now?

If you had a new source of income during the 2025/26 tax year, now is a good time to establish whether you need to register.

This is particularly important if you:

• started working as a sole trader;
• began receiving rental or other untaxed income;
• became a partner in a partnership;
• started a new business;
• have not previously submitted a Self Assessment return; or
• are unsure whether income received during 2025/26 needs to be declared.

The important point is to check the position before 5 October, rather than discovering close to the January filing deadline that you have not registered.

How SKN Chartered Accountants can help

Self Assessment can involve more than simply entering income and expenses into a tax return.

SKN Chartered Accountants supports individuals, sole traders, landlords, company directors and business owners with Self Assessment tax returns and related HMRC requirements.

We can help you establish whether you need to register, review the information that should be included in your return and ensure important deadlines are identified.

If you are based in Birmingham, the West Midlands, London or elsewhere in the UK, speak to SKN Chartered Accountants if you are unsure about your Self Assessment position.

Frequently Asked Questions

When do I need to register for Self Assessment for 2025/26?

If you need to complete a Self Assessment return for the 2025/26 tax year for the first time, HMRC says you should notify them by 5 October 2026.

When is the 2025/26 Self Assessment tax return due?

The deadline for submitting an online 2025/26 Self Assessment tax return and paying the tax due is 31 January 2027.

How quickly will I receive my UTR?

HMRC says taxpayers using its improved registration service can receive their UTR in their online account within approximately 72 hours.

Do accountants use HMRC’s new registration system?

No. HMRC states that the improved online registration journey is for individuals using their Personal Tax Account. Agents continue to use the existing registration processes, including CWF1 and SA1 where appropriate.

Need help with Self Assessment?

Unsure whether you need to register for Self Assessment before 5 October 2026?

Speak to SKN Chartered Accountants for professional support with Self Assessment registration, tax returns and your wider tax affairs.

Contact SKN Chartered Accountants today.

This article is for general information only and does not constitute personalised tax, legal or financial advice. Tax treatment depends on individual circumstances and legislation may change.