HMRC reports 40% surge in self-assessment tax forms filed on Christmas Day The build-up to the festive season saw an even larger increase with 14,330 filing returns, more than three-fold the figure of 4,115 for 2011. HMRC also said 73 of the forms were sent an hour before midnight. The figure was 4,685 for Boxing Day, up from 3,512 a year ago. Those paying typically need to pull together bank statements, P60 forms with last year's earnings and P11 forms of work benefits received. The process will be further complicated next year when those earning more than £50,000 will need to declare if they receive Child Benefit. The welfare payments are being withdrawn from families with at least one high earner. As Telegrapgh Money reported on Monday, HM Revenue & Customs (HMRC) is sending hundreds of thousands of letters to taxpayers telling them they will be fined £1,300 or more if they are late with returns. Around two million people were late filing returns last year. The warnings are being sent to the 850,000 people who missed the deadline last January and have still yet to comply. Since the rules were changed last year, you can be fined up to £1,600 for persistently failing to file, even if no tax is due. HMRC begins an "inner peace" advertising campaign this week aimed at encouarging taxpayers to get their forms out of the way. The penalties for late Self Assessment returns are: an initial £100 fixed penalty, which applies even if there is no tax to pay, or if the tax due is paid on time; after three months, additional daily penalties of £10 per day, up to a maximum of £900; after six months, a further penalty of 5pc of the tax due or £300, whichever is greater; and after 12 months, another 5pc or £300 charge, whichever is greater.