If you’ve just realised you’ve missed a tax deadline, first of all, take a breath. You’re not the first person to do this, and the situation is almost certainly more manageable than it feels right now. That said, HMRC penalties start immediately, escalate automatically, and still apply even if you don’t owe any tax. So, the best thing you can do is understand exactly what you’re dealing with and act quickly. Here’s what happens next.

 

What happens when you miss the tax deadline for Self-Assessment?

For most sole traders, landlords and company directors, 31 January is the date that matters most. It’s the online filing deadline AND the payment deadline for Self-Assessment. If you miss it by even a single day, you’ll incur an automatic £100 penalty, regardless of whether you owe HMRC a penny. That’s the bit that tends to sting most. We’ve had clients ring us genuinely baffled that they’ve been fined when they don’t even have a tax bill.

 

After that, the penalties can start piling up:

• 3 months late: £10 per day for up to 90 days. That’s a potential £900 on top of the initial £100

• 6 months late: the higher of £300 or 5% of the tax due

• 12 months late: a further £300 or 5% of the tax due

 

If your return is more than twelve months late, you could be looking at penalties of up to £1,600 before interest on any unpaid tax is added on. And interest, currently 7.75% per year, is charged daily on any unpaid tax from the day after the deadline until the day it’s paid in full.

Late payment carries its own separate penalty structure too: 5% of the unpaid tax at 30 days, again at 6 months, and again at 12 months. Filing your return on time but paying late doesn’t get you off the hook.

 

What to do if you’ve missed a deadline

File first, even if you can’t pay

This is the single most important thing to understand: filing your return and paying your tax are two completely separate obligations. If you’ve missed the deadline and can’t pay what you owe, file immediately anyway. Filing stops the late filing penalties from escalating any further, but the late payment penalties will continue to add up. We see clients sit on unfiled returns because they’re worried about the bill, and it always makes the situation worse. File first, then deal with the money.

 

Contact HMRC about a Time to Pay arrangement

If you genuinely can’t pay your tax bill in full, HMRC allows you to set up a payment plan. A Time to Pay arrangement lets you pay the debt in monthly instalments. While interest continues to accrue on the outstanding balance, the late payment penalty clock stops as long as you stick to the arrangement. The key is to contact HMRC before the situation escalates rather than after. In our experience, they are considerably more willing to work with people who approach them proactively than those who wait until enforcement action has already started.

You can find out more about Time to Pay arrangements on GOV.UK.

 

Consider whether you have a reasonable excuse

HMRC will cancel penalties where there is a genuine reasonable excuse for missing a deadline – but their definition of reasonable is fairly narrow. A serious illness, the death of a close relative shortly before the deadline, or a genuine HMRC system failure are all accepted. Being busy, not knowing about the deadline, or having a difficult few months financially are not. If you think you have grounds to appeal, you need to do so within 30 days of receiving the penalty notice using form SA370, and your return will need to be filed before HMRC will consider the appeal.

 

The clients who never panic in January

In our experience, the small business owners who sail through the Self-Assessment deadline every year aren’t necessarily more organised than anyone else but they do have two things in place:

1) a tax calendar with reminders set several weeks ahead of each key date, and 2) bookkeeping that’s kept up to date throughout the year rather than left for a frantic catch-up in December.

 

A good accountant should be reminding you of what’s coming before it arrives, not just helping you deal with the consequences after.

 

We’re here whether things have already gone wrong or you want to make sure they don’t

If you’ve just missed a deadline and need help getting things back on track, or you want to put systems in place so it never happens in the first place, we can help. Adams Accountancy works with sole traders, landlords and limited company directors across Kent and the South East.

Call us on 01322 250001 or get in touch online for a free, no-obligation chat. No question is too silly.

 

About the author

Michelle Adams is a qualified accountant and director at Adams Accountancy, a friendly, all-female practice based in Dartford, Kent. With over 15 years of experience helping sole traders, landlords and limited company directors across Kent stay on top of their tax obligations, Michelle and her team believe that no question is too silly and no deadline too far gone. Get in touch for a free, no-obligation consultation.

 

Frequently asked questions

 

Will I get a penalty even if I don’t owe any tax?

Yes. The initial £100 penalty applies automatically the moment the deadline passes, regardless of whether you have any tax to pay or are even due a refund. If HMRC has issued you a notice to file, you’re required to submit a return by the deadline whatever your tax position.

 

What counts as a reasonable excuse for missing a tax deadline?

HMRC accepts a serious or life-threatening illness, the death of a close relative around the time of the deadline, or a genuine and verifiable failure of HMRC’s own systems. Being busy, not knowing about the deadline, or having cash flow difficulties do not qualify as a reasonable excuse and any appeal needs to be made within 30 days of the penalty notice using form SA370.

 

What if I’m not sure I actually needed to file a return?

It’s worth checking, because if HMRC issued you a notice to file but you didn’t actually meet the Self-Assessment criteria for that year, you may be able to have the return and any penalties cancelled. Call HMRC on 0300 200 3310 or use the GOV.UK tool to check your filing requirement, and if you don’t need to file, follow the steps to have the notice withdrawn.

 

What happens if I just ignore the penalty notices?

Ignoring HMRC letters never makes the situation better and usually makes it considerably worse, as penalties and interest continue to accumulate and HMRC may escalate to enforcement action including debt collection or, in serious cases, legal proceedings. The best approach is always to engage early. Even a brief call to explain your circumstances opens the door to a more manageable outcome.