HMRC Self Assessment Deadline 5 October

HMRC has set a registration deadline of 5 October for the 2025/26 tax year. This is not the deadline for submitting a tax return.

What the Deadline Actually Means

By 5 October, certain individuals must inform HMRC that they need to complete a Self Assessment return for income earned between 6 April 2025 and 5 April 2026.

This applies even if you haven’t filed a return before or haven’t needed to in previous years.

Who Needs to Register?

Self-employed sole traders with over £1,000 in gross trading income
Business partners who must pay Capital Gains Tax
Individuals subject to the High Income Child Benefit Charge who don’t pay it via PAYE
People with untaxed income such as rental earnings, tips, dividends, or foreign income

What Counts as Untaxed Income?

Examples include:

Rental income from property or land
Tips and commission
Savings interest
Dividends
Foreign income

Side Hustles and the £1,000 Rule

Most side hustles with gross income under £1,000 do not require registration.

Gross income means total income before expenses are deducted.

Income from multiple side activities is combined. If your total gross trading income exceeds £1,000, you must register.

Important Exceptions

Some people may still need to register even with income under £1,000 to claim reliefs or benefits.

Activities like selling personal possessions do not count as trading. Regularly making or buying items to sell for profit does count.

Landlords and Property Income

Landlords must check their income level.

If you received rental income in 2025/26 and did not normally file a return, you must register by 5 October.

What You Should Do Today

Use HMRC’s online Self Assessment checker to determine if you need to act
If you need to register, do so via GOV.UK
If you were previously registered, consider reactivating your account instead of starting new

You do not need to complete your full tax return on 5 October.

What Happens if You Miss the Deadline?

If you missed the 5 October registration deadline, contact HMRC as soon as possible.

HMRC will typically give you three months from the date of their letter or email to file your return.

Missing the deadline does not automatically trigger a late-filing penalty. That penalty applies only when a required return is filed late.

Any tax owed for 2025/26 must still be paid by the deadline for the return.

For more details, visit the original source at Skint Dad.

Understanding your tax obligations helps ensure compliance and avoids penalties. If you’re unsure, use HMRC’s official tools to check your situation.

For side hustle income, remember the £1,000 gross income limit applies to all combined activities. This rule helps simplify reporting for small earners.

Registration is not a one-time event. It applies only to income earned during the 2025/26 tax year.

Even if you’ve never filed a return, acting by 5 October ensures you meet your legal obligations.