The charity - which supports the elderly - said the latest swindle targets older people in the city and tries to con them out of money by pretending to be a staff member of Age UK.
They said: "We were contacted by a person explaining their friend (in their 80s) in Sheffield was contacted by a scammer saying they were from Age UK.
"They asked about shopping, then asked if she was on her own and about her bank account and how much she had in it.
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"They then said a gentleman would call around to collect her card and number. At this point she realised this was a scam and put the phone down and told her friend. This was the right thing to do."
Age UK Sheffield has now put together a list of tips on how to spot and shut down such scams including: never give a stranger personal information or bank details; Age UK and other charities will never ask for bank details over the phone; if someone visits always ask to see identification; never share account log in details or passwords with anyone and if someone refuses to leave your property call the police.
Anyone who is contacted by someone who says they are from Age UK Sheffield can call 0114 250 2850 and staff will verify.
The National Fraud and Intelligence Bureau identified 21 reports of fraud relating to coronavirus between February and March, during which time scammers stole £80,000 from victims.