BT customers who have been affected by the raft of planned price hikes can leave their contract without having to pay a penalty charge.
Calls to BT landlines and mobiles are rising, along with monthly line rental and call plans, with the changes coming in to force on 20 September 2015.
BT broadband prices will also increase by almost 7%, the company said.
A Which? spokesperson said: ‘Telecoms companies will struggle to justify above-inflation price hikes unless there are significant improvements in customer service, especially to people facing mid-contract increases who thought the price they pay was fixed.
‘Unhappy BT customers who are affected have the right to leave without paying a penalty.’
Use our guide to leave your telecom’s provider penalty free if they hike their prices.
Leave your BT contract penalty free
Under rules introduced by Ofcom last year, if you took out a contract after 23 January 2014 and your provider hikes prices on that contract, you can cancel without paying any penalty fees.
BT has said customers who are part-way through a contract can leave for a rival provider without penalty, providing they do so within 30 days of receiving their price-hike letter.
Which? helped push for these changes with the support of more than 58,000 of you who felt it was unfair that millions of telecoms customers were being caught out by unfair price rises.
Together we convinced Ofcom to take action, and as a result fixed contracts mean fixed prices from the day you sign the agreement to the end of the contract.
This is the same for all telecoms providers including mobile phone, broadband and landline contracts.
However, if you were told at the point of sale that the price would definitely be increasing, it may be more difficult to leave without a penalty.
BT price increases in detail
BT said its price rises come on the back of similar increases by other telecoms providers, including Sky, TalkTalk and Virgin Media.
Among the increased charges are:
- Calls to UK landlines and 0870 numbers for customers not on call inclusive packages will rise from 9.58p a minute to 10.24p.
- The set-up fee for landline calls – charged each time a call is connected – goes from 15.97p to 17.07p.
- Calls to mobiles from a BT landline will rise from 12.77p to 13.65p a minute.
- Standard line rental is to rise from £16.99 to £17.99, while line rental plus goes up from £18.99 to £19.99.
- Unlimited anytime calls will rise from £7.45 to £7.95 a month for contracts before 20 June 2014.
- Unlimited evening and weekend calls go from £2.12 to £2.26 for the same customers.
- Unlimited anytime calls packages bought after 20 June 2014 will rise from £7.50 to £7.95.
- Unlimited evening and weekend calls go from £3 a month to £3.20.
- The cost of paper bills will increase from £1.59 to £1.70.