No surprise to see them following BT, Virgin etc.

"May 2011 changes
Some of our call charges change on 1st May but please note that they don't affect any calls (e.g. to 01, 02, 03 numbers, of 60 minutes or less) that are included in your package.

Chargeable calls that currently incur an 11.14p call connection charge will incur a charge of 12.5p. The cost of a daytime call to 01, 02, 03, 0870 and 0845 numbers is changing to 7.6p per minute.

From 1st May, TalkTalk Line Rental will be £12.60 per month. That's £1.30 per month cheaper than BT's recently-increased pay-monthly line rental. The price of Boosts will increase by 1 penny per month. "



https://sales.talktalk.co.uk/pricing/info/pricing-notification