HM Revenue and Customs (HMRC) oversaw the biggest digital Self Assessment event ever this year, receiving 10.24 million tax returns by midnight on 31 January – a record 85.5 per cent of which were sent online, it revealed today.


The busiest days for filing were 30 and 31 January, when HMRC received 980,000 returns. The busiest hour was between 1pm and 2pm on 30 January, when almost 50,000 returns were received – 830 per minute.


The busiest hour on deadline day was between 11 am and midday, when almost 32,000­­ returns were received – 530 per minute. HMRC also answered 95 per cent of calls first time on deadline day.


Around 4.3 million customers (42 per cent) left it until January to file their returns, which HMRC issued in April 2014.


By the end of January, more than a million Self Assessment-only customers (self-employed, with no other source of income, no employees and not VAT-registered) opted to receive electronic messages from HMRC, rather than paper communications. If you are eligible, you can sign up by logging into your Self Assessment online account and following the prompts.


HMRC’s Director General of Personal Tax, Ruth Owen, said:


"This is another record-breaking year for Self Assessment, with 210,000 more people filing their returns on time than last year.


“We're grateful to the overwhelming majority of people who sent their returns on time. If you’re one of the minority who missed the deadline, you still need to get your tax return to us as soon as possible, to avoid further penalties and interest mounting up.”


Missing the tax return deadline results in an automatic £100 late-filing penalty.There are further late-filing penalties after 3, 6 and 12 months. People with a genuine reason for not filing should contact HMRC to ensure they do not incur more penalties.


For anyone who still hasn’t filed their return, help and advice is available from the GOV.UK website at or the Self Assessment helpline on 0300 200 3310 (open 8am to 8pm, Monday to Friday, and 8am to 4pm on Saturday).


Customers with general tax return queries can tweet the @HMRCcustomers Twitter feed, from 8am to 6pm, Monday to Friday. Tweets should not contain any personal information.