What to do if you’ve missed the self-assessment deadline

What to do if you have a reasonable excuse for not filing your tax return on time and how to avoid further financial penalties

Despite the months of reminders and warnings, you may be one of the hundreds of thousands of small businesses owners HMRC estimates missed the self-assessment deadline on January 31.

While you now face a £100 fine, it’s not too late to file your tax return and avoid further penalties. Here’s what steps you need to take to complete your self-assessment after the deadline…

Don’t delay, complete your self-assessment return ASAP

Simply put, the longer you avoid completing your self-assessment, the more penalties you face – so the most important thing to remember is that you should do it as soon as possible after the deadline has passed.

You actually have three months to complete your tax return before the £100 fine increases, but don’t forget you’ll also incur interest if you’ve failed to pay your tax on time too.

Missing the deadline for self-assessment and failing to pay your tax bill on multiple occasions may make you vulnerable to inspection from HMRC inspectors. If you have failed to keep sufficient records of your finances, you can be charged up to £3,000 on top of penalties for late payments. However, this is reserved for cases where you have kept no records at all, if records have been deliberately destroyed or falsified, or if you have a history of failing to keep certain records.

To avoid this possibility and ensure you have enough information to complete your self-assessment, you should record your company’s assets, expenditure, purchases and sale or disposal of company assets.

What’s your excuse for not filing your tax return?

If you have what you consider to be a reasonable excuse for not completing your tax return on time, you should fill in and submit a claim form as soon as possible detailing what happened.

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HMRC defines a reasonable excuse as “something unexpected or outside your control”. For example: if a partner or close relative died shortly before the deadline or you had an unexpected hospital stay or a life threatening illness.

Other reasonable excuses include:

  • a computer or software failure while you were doing your return
  • a technical issue with HMRC online services
  • a fire, flood, theft
  • or unpredictable postal delays.

HMRC does not consider someone else’s failure to file your return, a failed payment because you didn’t have enough money, finding the online system too difficult to use or not getting a reminder from HMRC as a reasonable excuse.

Once your reasonable excuse is resolved, you must try to complete your return or payment as soon as possible.

Start preparing for next year’s self-assessment deadline now

The deadline comes round at the same time every year and the best way to avoid facing penalties is to keep an organised and easily accessible record of your accounts throughout the year and start filling in your self-assessment as early as possible. Remember, the better your record keeping throughout the year, the easier it will be to complete adequately and on time. Help yourself by setting aside an hour or more each week to look over your affairs and keep everything in check.

Filling in your self-assessment can be daunting and confusing, fraught with the possibility of unwittingly providing incorrect information and being penalised. If you don’t want to pay for an accredited accountant to complete it for you, HMRC is happy to answer general enquiries and offers plenty of guidance and explanation online.

There are also plenty of cloud-based accounting platforms available online designed specifically to help small and medium-sized business owners keep track of everything from their invoices and expenses to cashflow and tax.


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