From today (3 January), it will cost more to post a letter, but up to 50% less to send a parcel, even a large one.
Guernsey Post say the rates reflect how customers use the service.
Sending a letter, which has steadily declined in popularity, will become more expensive, but the money gained will help support the parcel post.
Those rates will either stay the same, or decrease in price, by as much as half.
Parcel post has increased in volume over the years due to the popularity of online shopping.
It will now cost £1.20 to send a letter to the UK, while parcel post rates stay the same or get cheaper:
Returns for goods bought online will be charged at a flat £5 for up to 10kg, while there's a 50% drop, or £30, in the price of a 30kg parcel.
Guernsey States committee presidents elected
WATCH: Fire ignites at Guernsey Waste site
Guernsey boy (3) wins regional art prize
Guernsey Post launches world first 'Cyberstamps' rather than 'Cryptostamps'
Team Guernsey gets Island Games send-off
Permission given for 69 homes on CI Tyres site
Members chosen for Guernsey's top political committee
Redundancies at Guernsey Post
