Guernsey Post is proposing to raise local, UK and international tariffs from April next year.
The Office of Utility Regulation will hold a consultation period from Wednesday for members of the public to comment on the changes.
Royal Mail is increasing its charges to £4.7m in 2006, Guernsey Post says tariffs need to rise to cover the cost.
If approved the price of a local stamp will rise from 26p to 29p, and a UK stamp will go up from 32p to 34p.
It would be the first rise in two years.
Martin Johnson, the finance director of Guernsey Post, says the Royal Mail previously subsidised the price of a local stamp, but because of the new charges local post rates must increase.