The number of phone scam reports being made tripled between December and January, figures from HM Revenue and Customs (HMRC) show.
The number of reports surged from 10,997 in December 2020 to 33,053 in January 2021, as people worked from home.
Reports of dodgy texts and emails also spiked last month as criminals tried to cash in.
Suspect text message reports climbed from 11,192 in December to 26,643 in January.
And phishing email reports rose from 39,564 in December to 46,210 in January, HMRC’s figures reveal.
Criminals pretending to be HMRC officials have been targeting taxpayers at the height of the self-assessment tax return period, usually offering bogus tax rebates.
They have also called people directly to threaten legal action over unpaid tax, or sent emails or texts offering fake support or grants.
A new scam variant involves criminals calling people to say that their National Insurance number has been used fraudulently. This allows scammers to either demand payment on a fake debt or to harvest victims’ personal and financial details.
Criminals have also taken advantage of Covid-19 to approach people with fake offers of Government support for people and businesses.
In the past year HMRC has responded to 259,675 reports of phone scams in total, up 31% on the previous year.
It has worked with the telecoms industry and Ofcom to remove more than 2,780 phone numbers being used to commit HMRC-related phone scams.
It has also asked internet service providers to take down 366 Covid-related scam pages and detected 387 Covid-related financial scams since March 2020, most of them by text message.
An HMRC spokeswoman said: “If someone calls, emails or texts claiming to be from HMRC, saying that you can claim financial help, are due a tax refund or owe tax, or asks for bank or other personal details, it might be a scam. Check gov.uk for our scams checklist and to find out how to report tax scams.
“If you can’t verify the identity of the caller, HMRC recommends that you do not speak to them.”
Here are HMRC’s tips to thwart scammers:
– Stop: Take a moment to think before parting with your information or money.
Do not give out private information or reply to text messages, and do not download attachments or click on links in texts or emails you were not expecting.
– Challenge: It is OK to reject, refuse or ignore any requests – only criminals will try to rush or panic you.
Search “scams” on gov.uk for information on how to recognise genuine HMRC contact and how to avoid and report scams.
– Protect: Forward suspicious emails claiming to be from HMRC to firstname.lastname@example.org and texts to 60599.
Contact your bank immediately if you think you’ve fallen victim to a scam and report it to Action Fraud.