The cost of having a landline has risen by more than a third in the past five years, adding £50 to a year to bills.
Broadbandchoices.co.uk found that the average cost of having a phone line has risen by 38% since April 2009, with customers now paying on average £15.35 a month - up from £11.14 five years ago.
The biggest price increase has been for Virgin Media customers, who pay £15.99 for their landline, a change of 45%. Next was BT (£15.99, a 42% increase) and Sky (£15.40, a 40% increase).
Landlines are becoming increasingly redundant for people, with fewer and fewer of us using them to make calls.
The research found that 37% of people would get rid of their phone line if they didn't need to have one for their broadband services.
Only 22% said they regularly make calls from their landline, while 10% said they didn't even have a phone plugged-in.
Dominic Baliszewski, of Broadbandchoices, said: "Most of us are accustomed to price rises, but line rental is really suffering from an image crisis at the moment. People are quite rightly questioning why they're being asked for more money time and time again.
"The situation isn't helped when the status quo for providers is to charge one price for line rental and a separate additional fee for broadband on top. This gives the impression line rental is only for home phone, when in fact it's essential for most people's broadband."