Horsham police are warning residents to be aware of potential fraudsters following 15 reported incidents in four days.
Police said scammers are pretending to be from banks, the police and other organisations as well as posing as Trading Standards officers or court officials claiming they can help recover losses from previous crimes.
Residents have been warned not to give out any personal information and instead contact police.
Inspector Clare McKnight said: “Thankfully, people are mostly alert to this nasty crime and none of the attempts were successful, but it is important that everyone is aware that the fraudsters and scammers are particularly active in this area currently.
“In addition to claiming to be from banks, police or other organisations, there have been reports elsewhere in the county of people posing as Trading Standards officers or court officials, claiming to be able to help recover losses from previous crimes.
“If you are approached by telephone or by cold call at the door by someone who asks for money as part of a refund or compensation for rogue trader problems, do not pay any money or give any personal details. Do not reveal bank card PINs or agree to have a bank card or money collected by a courier. Genuine organisations never ask you to do this.
“Instead, contact Sussex Police via firstname.lastname@example.org or by calling 101 or if the suspect has arranged to call on you or has done very recently, dial 999 immediately.
“These criminals do target the most vulnerable members of our community, so please alert your relatives, neighbours or friends who you think might be susceptible to such an approach.”