The cost of sending a letter from the Bailiwick of Guernsey to the UK will go up from August.
Guernsey Post's proposed new prices have been agreed by the industry regulators, the Office of Utility Regulation (Our).
A letter under 100g will rise by 2p to 47p, the minimum for heavier letters by 3p to 61p and the minimum for packets will increase from £1.20 to £1.29.
The costs of sending mail within the Bailiwick will be unchanged.
All international prices for bulk and public services are also to remain the same.
Boley Smillie, chief executive of Guernsey Post, said the increase "was driven solely by an increase to Royal Mail's postal rates".
He said: "The new tariff also continues to benefit from our extensive savings programme that was agreed by the Our earlier this year."