Cheshire Police have recently arrested three people who are suspected of stealing post from residential post boxes.
Sgt Andy Miller said "The theft of this post appears to have been to enable them to commit further offences by taking control of victims' bank accounts and then committing fraud.
"Members of the public in the Wilmslow, Prestbury, Knutsford and Poynton areas are urged to check on the security of their post boxes to ensure that post can not be removed from them after it has been placed inside."
Several Incidents took place in Styal at the beginning of February, which included a number of post boxes being broken into on Hollin Lane.
One local resident who wishes to remain anonymous told wilmslow.co.uk said "I didn't think anything of it until a PIN number for a Barclaycard came - I had never had or applied for a Barclaycard.
"I phoned Barclaycard and a card had already been sent but I never received it. A bill later came for £5000 spent at a cash and carry in Birmingham. Barclaycard weren't interested in contacting the police about it. I also had an account applied for in my name for Ulster Bank.
"My next door neighbour also had two accounts applied for at the same time. It's very difficult to say what other mail is missing as lots of bills are paperless these days but we do know a credit card statement is missing."
Please contact police on 101 if you see anything or anyone suspicious in your area.