UK self-assessment deadlines for expats

If you are an expat with assets in the UK, e.g. rental property, you may be required to complete an online self-assessment tax return.

Key dates/deadlines to know are as follows.

January 31 – The final deadline for online self-assessment tax returns.

However, if you think any of the information entered on your tax return is inaccurate, amendments can be made up to 12 months after this date.

As well as filing your return, you must also pay your full tax bill by midnight on January 31. Failure to do so will result in interest of 3pc on any unpaid tax being added to the bill.

If you miss this deadline, even by a second, you will automatically incur a £100 fine, even if you don’t owe any tax. After this time the penalty structure gets extremely complicated.

HMRC in their infinite kindness, do offer an online calculator so you can work out how much you owe them in fees and interest.

March 2 – If you still haven’t paid your tax bill by March 2, HMRC will impose a surcharge of 5pc of the tax owed.

April 31 – If you haven’t filed your return by this date, a £10 daily charge begins, up to a maximum of £900.

31 July – After six months, HMRC will charge a penalty of 5pc of the tax due or £300, whichever is higher. This means that anyone who fails to file a return before this deadline could face total penalties of at least £1,300.

The penalties start to become even more serious if the tax return is more than 12 months late and can be as much as 200pc of the tax owed.

5 October – This is the deadline to tell HMRC that you need to register for self assessment for the current tax year.

31 October – If you want to file your tax return on paper instead of online, it must be submitted by 31 October.


You can get more help and advice on filing your return, including how to register for online filing either from the HMRC website or the Self Assessment helpline +44 300 200 3310.