Scammers pretending to be from Caerphilly County Borough Council are phoning and texting residents claiming a refund is due.
The council has warned residents not to provide their bank account details if they receive any messages or calls saying their council tax account is in credit.
Some of the tricks used by scammers include charging an upfront fee, insisting your property is in an incorrect band and asking for bank details.
The council has reiterated that it never cold calls residents asking for bank details.
To check if you are eligible for a refund, contact the council tax office on 01443 863006 or email firstname.lastname@example.org.