A local stamp will cost 20p more from 28 January, while the price of sending a letter to the UK rise to £1.35.
Jersey Post is putting up the price of a stamp by a third, from 60p to 80p.
A UK stamp (for letters up to 100g) will rise from 98p to £1.35.
Jersey Post says the current prices have been held for two years, but need to go up because of above-inflation cost increases from its suppliers.
We're sending far fewer letters than we used to - a trend that is happening globally - and Jersey Post says higher postage for this type of mail is necessary because of those declining volumes.
Sending a letter to Europe will be around 7% more, and to the Rest of World up by an average of 1.7%.
However, the price we pay for posting parcels is going down.
Jersey Post says it will be around 18% cheaper to send a parcel to the UK, 12% less within Jersey and 14% cheaper to Rest of World.
Parcels to Europe will be almost unchanged, with a 1% reduction.
Mark Siviter, Jersey Post Group CEO, says: “We remain committed to providing islanders with accessible postal services. However, we’ve had to make some tough decisions to ensure we have a sustainable and viable service for the future.
“We need to cover the costs of running our Post Office network, and think it’s right we pay our hardworking posties the living wage. Where possible we’ve reduced our parcel pricing to support customers and local businesses and are introducing a range of volume based discounts for businesses.”
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