Customers are losing £5.8bn per year by sticking with the same mobile supplier, according to research from comparison site uSwitch.
One-quarter of mobile users have never switched mobile network, according to the survey of 2,000. For those over the age of 55, the proportion rose to one-third.
If extrapolated across the population, uSwitch estimated 3.5 million people haven’t moved network in the past three years. The average yearly saving of switching providers is £176, it said.
Almost half of mobile users haven’t a clue what a Porting Authorisation Code (PAC) is, required to port mobile numbers to your new providers.
Ernest Doku, telecoms expert at uSwitch.com, said the process of moving to another network remains "baffling" for many customers.
He said: "As it stands, the responsibility falls to the customer to contact their current provider to request their PAC - and more than likely having to run the retentions gauntlet.
"Unless you can’t get a signal, for many it may feel this is simply not worth the effort - the upshot being they’re likely to just stick on their current plan, and miss out on potentially huge monetary savings or a better suited tariff."
Ofcom is looking to make this process easier. Doku said the changes should make providers work harder to win and proactively win business.
A separate survey from uSwitch found that one-third of customers were unprepared to switch broadband providers out of fear risk a prolonged period without access to the web.
Another survey by Cable.co.uk, found that one-third had only ever been with one broadband provider. ®