The scourge of scam texts and calls has been laid bare by UK telecoms regulator research showing almost 45 million people received at least one in the last three months, while mobile network EE had to block 18,000 sim cards used for the fraud over that period.

Research by Ofcom found that 82% of adults had received a suspicious message during the summer, with most reporting that it had come via a text.

Landline calls continued to be a threat for older people, with 61% of over-75s saying they had received a potential scam call.

Scams have boomed since the start of the pandemic, with fraudsters capitalising on changing consumer habits over the period.

Texts and emails purporting to be from courier firms and messages offering access to Covid vaccines and passports have been among the tricks used by criminals to get hold of people personal details.

Recently the trade body for banks, UK Finance, said £754m had been stolen from bank customers during the first half of this year. Readers of the Guardian have alone reported £1m worth of losses to us over the summer months.

The use of mobile phones in the frauds is underlined by figures from EE which show it has blocked 18,000 sim cards after detecting 42m scam text messages since July.

The firm, which is owned by BT, uses scanning technology to track down and block suspicious looking messages.

BT’s customer care change director, Christopher Howe, told the PA Media news agency that many of the sims that have been barred were on pay-as-you-go deals.

Rocio Concha, the director of policy and advocacy at the consumer group Which?, said Ofcom’s research showed that fraudsters were “relentless in their efforts to trick people into giving away their money and personal information”.

She added: “Businesses and the telecoms industry must do more to protect consumers, by making it harder for fraudsters to exploit systemic weaknesses to reach potential victims and by improving how they use telecommunications to reach their customers.”

Lindsey Fussell, Ofcom’s networks and communications group director, said: “Criminals who defraud people using phone and text scams can cause huge distress and financial harm to their victims, and their tactics are becoming increasingly sophisticated.

“Stay alert to any unsolicited contact. Put the phone down if you have any suspicion that it is a scam call, and don’t click on any links in text messages you’re unsure about.”

Ofcom said suspicious texts could be forwarded to 7726 and would be investigated by mobile phone providers, while scam calls could be reported to Action Fraud or Police Scotland.