BT says the decision to increase the cost of its Line Rental Saver scheme has nothing to do with its recent move into sports broadcasting.
At present, customers paying for line rental 12 months in advance are charged a one-off fee of £129. However, this is rising by nine per cent to £141 for new customers.
BT has faced external criticism over the move, with some commentators pointing to the firm's heavy investment in Premier League football rights.
The company - which launches its BT Sport platform in August - has paid £736 million for 38 live top-flight matches per season, for three years from 2013-14.
And when the channels launch, all BT broadband customers will be entitled to free access, as the firm aims to increase the pressure on its major rival Sky.
However BT has denied it is hiking the cost of annual line rental to pay for its football coverage.
A spokesman for the firm said: "Paying upfront for line rental has proved popular with our customers and is substantially cheaper than the cost of standard line rental offered by major rivals such as Sky, Virgin Media and TalkTalk.
"This increase, the first for 14 months, does not affect existing Line Rental Saver customers."