October 31 is the date on which paper returns must reach HMRC for tax year 2013/14 (April 6, 2013 to April 5, 2014).
Late filing will result in a penalty of £100, irrespective of whether there is or isn’t any tax to pay.
Longer delays of three, six and 12 months bring further fines.
But opting to file returns online extends the deadline by three months until January 31 without a fine until after that date.
However, it can take up to 21 days to register and receive the necessary activation code for those living outside the UK.
The sign up process for online self-assessment can be completed at gov.uk. Expats should fill in a self-assessment return if they have UK-based income generated, such as rental revenue from a property there or investment returns from UK funds.
For HMRC a spokesman said: “As well as having an extra three months to send your return, filing online means your tax is calculated automatically and your return is processed faster. This means any tax refund you’re due is repaid more quickly. ”
