Mobile network EE has blocked 18,000 SIM cards after detecting some 42 million scam text messages since July.
Providers have been battling a wave of bogus SMS communications during the pandemic, particularly around parcels and PCR Covid-19 testing but also related to the petrol crisis more recently.
The BT-owned firm has invested millions in a new anti-spam filter which can identify and limit the spread of scams, after some customers were tricked into parting with thousands of pounds.
Scanning technology looks out for certain traits, such as the construct of the message, whether the number is sending out huge volumes, and looking out for dodgy web addresses.
The number of EE customers reporting scams since the system was introduced has fallen by 85%.
BT’s customer care change director, Christopher Howe, told the PA news agency: “The environment and the landscape of scamming has changed and that’s really brought us to where we were earlier this year.
“During Covid, the chances of receiving a parcel on a day-to-day (basis) significantly went up because we all started ordering more online, but I think it’s just exploiting life events.
“What the scammers do is they try and pick on emotional vulnerabilities and exploit those.
“Sadly we have seen a number of customers who have fallen into financial hardship or certainly had a significant financial impact because of this. It’s the age-old story – they’ve provided personal details or banking details and then that scammer has then really impacted them; that’s why it’s so important for us to protect our customers.”
Many of the SIMs that have been barred are pay-as-you-go.
It came as Ofcom said an estimated 44.6 million adults in the UK have received a suspicious message in the form of a text, recorded message or live phone call to a landline or mobile over the last three months.
A survey by the regulator suggested text scams are the most common, with seven in 10 saying they had received one.