What to do if you've missed your self assessment deadline

If you missed the self-assessment deadline, you’re not alone.

HM Revenue & Customs estimates 750,000 people a year out of the 11.5 million who should file the paperwork fail to lodge their self-assessment returns before the midnight on 31st January cut-off.

The bad news is, you will likely have to fork out at least £150 in fines. The good news? You don’t have to panic. If you can pay those penalties, there is still e time to sort out your tax affairs.

So, if you didn’t file on time, what now?


What are the penalties for self-assessment late-filing?

Unfortunately, if you have missed the 31st Jan deadline (and if you’re reading this, you probably have), you will almost certainly incur a fine. HMRC charges two sets of penalties for missing the self-assessment deadline:

  • £100 for not filing the return on time. This is an automatic fine which applies regardless of whether any tax is owed or not. If you still don’t file a return, the next penalty is imposed on 1st May.
  • £50 if you didn’t pay your tax on time, followed by a fine of 5% of the tax owed if the bill is still unpaid 30 days later (which again is 1st March, depending on the number of days in February.)

If you don’t fill in your self-assessment or you don’t pay your tax, the penalties will increase. To find out how much you may have pay in penalties for the current tax year, use the HMRC online tool for an estimate.

Of course, not everyone can file on time, and if you have a good enough reason for missing the deadline, you can appeal to HMRC. ‘The dog ate it’ or ‘I spilt coffee on it’ won’t fly, HMRC will only listen to events that happened unexpectedly or that were beyond your control. These include:

  • The death of your partner or a close relative shortly before the filing deadline
  • An unplanned hospital stay
  • Suffering a life-threatening illness
  • A computer or software failure at the time of filing your return
  • The HMRC online service was unavailable

If you believe you have a valid reason for not filing your return, contact HMRC on 0300 200 3822 to explain why and ask for more time.

If you don’t have a reasonable excuse for missing the deadline, it’s not the end of the world. But, of course, we recommend getting your taxes in order as soon as possible.

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Stopping the self-assessment penalty clock

HMRC has a time-based system for imposing penalties, so the earlier you stop the clock, the less you have to pay. Tax professionals do this by filing a return with estimated figures then going back later to amend them with the correct information. This method is a quick win, and perfectly above board.

If you haven’t even started filling in the return, for instance, this at least gives you some breathing space to go back and get the figures right further down the line.

HMRC rules say this is OK if you explain the figures are provisional in the additional information box on your self-assessment return and give a date when the up-to-date information will be posted online.

The rules say you have until 31st January 2021 to amend a self-assessment return due on 31st January 2020.

You should pay any tax due when you file the estimated return as well.

If you overpay, HMRC will refund the extra plus interest. Should you underpay, penalties and interest will be due.

 What to do if you've missed your self assessment deadline | Woman checking the time on her watch by desk with calculator and laptop

Filing a late self-assessment return

The majority of landlords will complete their tax returns digitally anyway, but even though you may prefer paper, our advice is to carry out the process online.

Why? The deadline for paper returns was 31st October, and the fines for late return accumulate over time. If you fill your return in online now, the penalty will be £150. If you decide to submit returns by post, it will cost you more like £900. That’s a £750 reason to file digitally.

You can only file your return and pay tax online if you are registered with the Government Gateway or Gov.uk Verify.

If you have filed a self-assessment return for another year, you already have log-in details. This is not the same as registering for self-assessment.

If you are filing online for the first time, you need to sign up at Gov.uk for an activation code, which can take up to ten working days to arrive in the post. You need to have filed a tax return to pay any tax due so step one is to get into the online portal.