HMRC is warning people to be the alert for scams in run-up to the tax Self-Assessment deadline after receiving over 900,000 reports from the public about potential scams last year alone.
More than 100,000 of these have been phone scams, and more than 620,000 have been about bogus tax rebates.
Common techniques to watch out for include emails and text messages offering refunds with clickable links. These usually lead to "phishing" websites.
It is easy to see how fraudsters can take advantage of taxpayers rushing to paying their tax bill"
Other methods which have been used include a pre-recorded messages, allegedly from HMRC, claiming action is being taken to recover unpaid tax. Calls from numbers which look identical to HMRC are also increasing. They can even include Government Gateway account numbers.
Mike Haley, CEO of Cifas, a fraud prevention service, said: "With the self-assessment tax return deadline fast approaching, it is easy to see how fraudsters can take advantage of taxpayers rushing to paying their tax bill - especially if they are being threatened with legal action out of the blue.
"If you are contacted by someone claiming to be from HMRC then don't respond, and remember never to give out any personal details, download attachments or click on links.
"If you receive an email or text, then report it to HMRC straight away so they can take the appropriate action to help prevent others losing their cash to criminals."
Last year alone, HMRC's cyber security team took down and investigated 8202 malicious websites and phone lines that were thought to be scammers. The team also worked to removed 1921 unique numbers that were being used by scammers.