HMRC figures show the huge scale of the problem. HMRC has requested the removal of over 20,000 malicious websites and this year alone HMRC’s cyber security team has taken control of 75 dubious site by challenging their ownership.

Many of the websites promote misleading and costly helpline numbers which simply link to free or standard cost HMRC numbers. The tax collector also says that when someone searches online for HMRC’s phone numbers or digital services they can be directed to other, often malicious websites.

Some of these promote premium rate, non-HMRC numbers as a means of reaching the organisation. These are often call forwarding services which connect callers to HMRC, but at a hefty price, despite HMRC’s own 0300 numbers being free or charged at the national landline rate.

In other cases, sites charge for forwarding information to HMRC which can be provided free of charge through gov.uk. Too often this is an attempt to mislead customers and gain business at their expense, says HMRC.

Any members of the public trying to access the 75 sites taken control of this year will now be redirected to HMRC’s gov.uk pages, which provide HMRC’s genuine contact numbers as well as advice on how to spot these misleading sites.

Through this work, HMRC says it has redirected over a million customers to gov.uk, averting a potential one million visits to malicious or misleading websites.

HMRC’s director for customer services, Angela MacDonald, said: “HMRC takes the abuse of its brand very seriously. Attempts to dupe customers in this way won’t be tolerated and we will always act to protect the public from malicious or misleading websites.”