Missed the Self-Assessment Deadline? Don’t Ignore This.

A practical UK guide to Self-Assessment late filing penalties and how to fix them.

Missing the 31 January Self-Assessment deadline is more common than you think-

but ignoring it can become expensive very quickly.

HMRC applies automatic penalties immediately. Even if you owe no tax, you can still receive a fine.

If you've missed the deadline, the most important thing is to act now.

What is the Penalty for Late Self-Assessment?

If you fail to submit your Self-Assessment tax return by 31 January (online deadline), HMRC will issue:

• £100 Automatic Fine

This applies even if:

You owe no taxes

You are due a refund

No reminders. No warnings.

What Happens After 3 Months?

If your return is still not filed:

• £10 per day penalty

• Up to £900 additional fine

The total penalties could now exceed £1,000.

6-Month and 12 -Month Penalties

After 6 Months:

• £300 or

• 5% of the tax due (whichever is higher)

After 12 Months:

• Another £300 or

• Another 5% of the tax is due

Penalties increase the longer you delay.

What If You Filed But Didn't Pay?

Late payment triggers:

• 5% of unpaid tax after 30 days

• Another 5% after 6 months

• Another 5% after 12 months

• Interest charged daily from 31 January

HMRC does not wait.

Can You Reduce Self-Assessment Penalties?

In some cases, yes.

You may be able to:

• Appeal penalties if you have a reasonable excuse

• Set up a Time to Pay arrangement with HMRC

• Reduce additional charges by filing immediately

The sooner you act, the more options you have.

Don't Let a Small Delay Become a Serious Problem

Ignoring HMRC letters can lead to:

• Increased penalties

• Estimated tax bills

• Debt colletion action

Most issues can be resolved quickly - if handled properly.

We Help Clients Fix Late Returns Fast

At Lukvitax, we support individuals, freelancers, landlords and small businesses across the UK with:

• Overdue Self-Assessment tax returns

• Penalty appeals

• Payment plans with HMRC

• Compliance letters and investigations

If you've missed the Self-Assessment deadline, don't panic - but don't delay.

👉 Book your free initial consultation today, and let's resolve it professionally.

This article provides general information only and does not constitute personalised tax advice. Professional advice is provided following a formal engagement.