BT, Sky and Virgin Media have announced plans to close a loophole on their phone networks which lets criminals dupe people into revealing sensitive information.
The call clearing feature can be used to make it appear as if customers are receiving calls from their bank, ISP or the police.
Scammers trying to abuse this feature typically call a victim pretending to be from a legitimate company or organisation asking to confirm credit card details. The scammer would tell the victim to verify that the alert is genuine by ringing another number.
Call clearing was set up to help transfer calls from one extention to another in homes by keeping a line open even after the customer hangs up. Typically, a call clearing window is several minutes long.
If the call is made from the same phone line before the call clearing deadline has passed, the caller will still be connected to the scammer who can trick them into thinking the verification is genuine.
Now BT, Sky and Virgin Media plan to cut these clearing times from minutes to seconds to prevent the misuse of the loophole.
A BT spokesman told the BBC that while the requirement for call clearing has decreased the feature still keeps lines open form two to three minutes.
“We intend to cut the ‘holding the line open’ time to two seconds and we will have a solution in place to do this for several million customers over the next six weeks,” a BT spokesmand told the BBC.
“We need to do some further testing for the remaining lines and will resolve this issue for those customers as soon as possible.”
Virgin is also investigating ways to cut down clearing times on its phone network. Virgin Media spokesperson Emma Hutchinson said: “If someone is concerned about a call they’ve received, they should hang up and either wait five minutes or use another line to speak to the police on 101.”
TalkTalk said that it had already cut the call clearing window down to a matter of seconds months ago. Recently, the UK’s fourth biggest ISP by subscriber size made a number of privacy features free to access, a move that was enthusiastically received by its customers.