Sure cut Guernsey's two-minute open-line scam window to a few seconds
Guernsey's sole fixed-line supplier re-engineered its network so lines close in seconds, not two minutes, sealing fraudsters' interception route.
What was changed
Until fixed-line competition opened in Guernsey in June 2015, Sure was the island's only supplier of fixed line services. Its system kept lines held open for up to two minutes even after a caller had put down the receiver, leaving islanders vulnerable to phone scams in which fraudsters could intercept the open line.
Hundreds of thousands of pounds were scammed out of people in Guernsey in 2015, and the island's police worked with Sure to resolve the issue. The company carried out major work on its network to close the window.
Sure says phone lines now remain open for just a few seconds, making it impossible for calls to be intercepted. It still urges customers to stay vigilant, never hand over banking credentials, and report suspicious activity immediately.
Why it worked
Sure's monopoly-era system design left lines open for two minutes after hang-up — a default that became a fraud vector once scammers targeted the island.
Police confirmed losses in the hundreds of thousands of pounds in 2015, making the fix an operational priority rather than a routine upgrade.
Competition arrived in June 2015, ending Sure's fixed-line monopoly and raising the cost of a known security weakness.
What can be applied
A monopoly-era network default quietly became a fraud enabler; shrinking the technical exposure to seconds beat telling customers to be careful.
Aftermath
The re-engineered network keeps lines open for only a few seconds, which Sure says makes interception impossible. The company continues to urge customers to be vigilant and to report suspicious activity immediately, alongside published advice — sourced from RBS in the BBC's report — to end unexpected calls asking for PINs or banking credentials and to verify callers on an independently-checked number.