The number of people taking to the internet on Christmas Day to fill out their tax returns jumped by 40% this year, HM Revenue and Customs (HMRC) has said.
A total of 1,548 people took time out from their turkey and presents to file their returns, compared with 1,100 taxpayers on Christmas Day 2011.
Christmas Eve was also a popular day for sorting out tax affairs, with 14,330 people sending an online tax return - more than treble the number who did so on the same day a year earlier.
And as the Boxing Day sales kicked off, 4,685 people decided to sit down at their computers and send their tax return over the internet, representing a year-on-year increase of a third.
A new HMRC campaign is urging anyone who still has not sent in their 2011-12 tax return to do so as soon as possible.
It forms part of HMRC's efforts to encourage 10.6 million people in self-assessment to submit their return online by the January 31 deadline.
The penalty for a late self-assessment return is a £100 fixed charge, which applies even if there is no tax to pay, or if the tax due is paid on time.
After three months there are additional daily charges of £10 per day, up to a maximum of £900, and after six months there is a further penalty of either 5% of the tax due or £300, whichever adds up to more.
After 12 months, late payers are hit by another 5% or £300 charge, whichever is the greater.