Tax returns Late tax returns and penalties for mistakes

Letters lying on a doormat

If you miss the deadline for filing your tax return or paying your bill, you could face harsh penalties

Penalties for filing your tax return late

You will be fined if you miss HMRC’s tax return deadlines – and the penalties can be high.

If you miss the final deadline to file your 2011-2012 return HMRC will charge you £100.  

If your return is still outstanding six months later, you’ll be charged another £100. However, the penalties imposed on you will not exceed the total amount of tax you owe.

You can read more about the deadlines for filing online and paper tax returns on the 2011-12 tax returns page of this guide.

Don't submit two tax returns!

If you miss the 31 October 2012 deadline for paper returns, you can still register to file your return online, giving you until 31 January 2013 to get it in.

But watch out – if you submit a paper return after 31 October and incur the £100 fine, submitting an online return as well will not cancel the penalty. You can only file one tax return per year.

Very late tax returns

If your return is seriously late, you might also be charged a further penalty of up to £60 a day, but only where HMRC has permission to impose this penalty from the Special Commissioners. If this happens, the penalty you're charged can exceed the total tax you owe.

Late payment penalties

Things only get worse if you also fail to pay your tax bill on time. The deadline for paying tax for the 2011-2012 tax year is 31 January 2013. If you miss this deadline you’ll be charged interest from the date the payment was due. The interest rate varies – you can check the current rate payable on HMRC's website.

If any of the tax bill remains unpaid by 28 February 2013, you’ll be charged a 5% surcharge. An additional 5% is imposed on any of the tax bill which is unpaid by 31 July 2013.

Incorrect return penalties

The system of penalties for mistakes on your tax return has changed. For tax returns for periods beginning after 1 April 2008 the penalty depends on whether HMRC thinks you have been careless or have tried to mislead them. 

Penalties are based on the amount of tax you owe, and are payable in addition to the tax owed.

  • If you have taken reasonable care to fill in your return correctly, you’ll have no penalty to pay.
  • If you have been careless, the penalty will be between 0% and 30% of the extra tax owing.
  • If you have deliberately underestimated your tax, the penalty is between 20% and 70%.
  • If you have deliberately underestimated your tax and attempted to conceal the fact, the penalty will be between 30% and 100%.

Penalties may be reduced according to how much you cooperate with HMRC. The HMRC website can provide more information on this.

For further guidance on how to fill in the self-assessment form on paper, as well as advice on all aspects of the UK tax system, buy a copy of the Tax Handbook 2012/13.

Get help with filling in your tax return

To help taxpayers complete a return correctly, HMRC produces a 28-page guide, How to fill in your Tax Return (SA150).

Online demonstration

There is also an online demonstration of the self-assessment process, and HMRC has a podcast explaining how to complete your tax return. Additionally, HMRC produces a range of other help documents.

Phone, written and face-to-face help

Taxpayers can get help from HMRC in writing, by telephone and face-to-face at HMRC offices.

  • The Self-Assessment Helpline (0845 900 0444) can offer general tax advice, and help with filling in your tax return. The service is open seven days a week, from 8am to 8pm.
  • If you’re having technical difficulties filling in your return online, contact the Online Services Helpdesk (0845 605 5999) for help. The service is open all week from 8am to 8pm.
  • If you are struggling to pay your tax on time, you can contact HMRC’s Payment Helpline on 0845 366 1204 for advice.
  • You can write to or visit your local tax office. To find your local HMRC office, use the HMRC tax office locator.

If you have complex tax affairs, you may also want to consider getting help from a qualified tax adviser. You'll find useful information about finding one on the Choosing a tax adviser page of this guide.

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