Nine out of ten people in the UK receive between five and 30 nuisance calls per week - one in five end up victims of scams.
Fraudsters rake in huge sums as a third of people lost up to £50, a fifth between £100 and £500, while one in eight got scammed for up to £10,000.
See also: Holiday firms rapped for misleading ads
CPR Call Blocker has identified the top five telephone scams people get caught out by - the calls you need to be very wary of.
Top 5 telephone scams:
Being called by so-called Microsoft Windows Support saying your computer has a virus and they need your passwords to fix it. Don't ever give anyone your computer password.
A crook claiming to be from your bank or HMRC saying there's a problem with your account or tax bill and they need your security details, including your PIN. A bank or HMRC will never ask for PINs.
An offer of an unmissable investment or the chance to access pension savings early.
Messages asking you to call back after a missed call - and the number is a premium rate line.
Being told you have won a large prize and being asked to pay a processing fee or to call a premium rate line to claim your prize.
How to protect yourself
Don't assume anyone who has called your phone or left you a voicemail message is who they say they are.
If a phone call or voicemail offers you a deal, asks you to make a payment or log-in to an online account, be cautious.
If in doubt, check it's genuine by asking the company it claims to be yourself. Never call numbers or follow links provided in suspicious emails; find the official website or customer support number using a separate browser.
Stop the rogues
If you have any doubt at all about a caller being genuine put the phone down.
The only way to help stop fraudsters from stealing money is to report suspected fraud/scams to Action Fraud at actionfraud.police.uk or by calling 0300 123 2040.