You will find more information on fares, address of your local post office and opening times on the website: http://www.post.be
Most common stamps (A) do not show a price, and therefore have no limit on validity. The standard price, for a maximum weight of 50g, is currently €0,50 (D+1) or €0,40 (D+2 - non prior). Careful, this rate is only valid for standard mail (with conditions on weight, thickness and size). For the rest, it is better to see the different fares directly on the website. For Europe, the price for a standard letter is €0,70 (€0,60 non prior). For the rest of the world: €0.80 (€0,65).
The Post office provides several services to facilitate your change of address:
It is also possible to access a banking service with the Belgian post : http://bpo.post.be (BPO - Banque de la Poste).