Her Majesty's Revenue and Customs (HMRC) intercepted more than £96m ($138m) worth of fraudulent or incorrect repayment claims with new technology, the government said. HMRC claimed its data system identified more than 17,000 unjustified repayment claims.

In total, 3.4 million returns were checked by HMRC, representing a third of the total 10.39 million tax assessments filed. It checked online as well as paper forms filled by those who did their tax return.

"Our success in using cutting-edge technology to sift and sort through millions of pieces of data is stopping fraudulent repayments in their tracks," said Jennie Granger, HMRC's head of enforcement and complience. "Our highly skilled tax specialists are experts at reacting quickly to identify suspicious activity, protecting tax revenues that fund essential public services."

A record 89% of people filing tax returns did so online on HMRC's website, the government revealed. In total, 10.39 million self-assessment tax returns were completed ahead of the deadline of midnight on 31 January.

Filing in paper is obviously considered outdated, as 9.24 million people (89%) went to HMRC's website to file their tax return, compared to 2015's 8.76 million (85.5%) online filings. Some 92% of people who had to fill out tax returns did so before the deadline, HMRC has said.

"We all know it's easy to put off completing your self-assessment tax return, which is why it's fantastic to see more customers than ever before completing theirs on time this year," Ruth Owen, head of personal tax at HMRC commented. "Each year we're dedicated to making the self-assessment process easier and more intuitive."

At its busiest hour, between 2pm and 3pm on 29 January, HRMC received 50,358 returns, or 839.3 per minute and 13.9 per second. On average, the department received 21,386 files per hour that day.

The majority of tax returns were filed before the turn of the new year. Only 43% left the assessment to January 2016.