The scheme was due to end tomorrow
Bus fares will remain capped at a maximum of £2 until the end of March.
The three-month trial began in November as part of measures to support residents and businesses through the winter.
The scheme was due to end tomorrow but has now been extended while a review of pricing is concluded.
Commenting on the extension, Infrastructure Minister Chris Thomas said the fare cap has resulted in a small increase in passengers and seen added value and savings for existing users.