What postage is needed for wedding invitations in the UK?

Postage depends on three things: the size of the envelope, its weight, and whether you choose first or second class. A typical A5 or A6 invitation with a single card and envelope usually fits within standard letter size and weight, so one stamp is enough. But if you add a response card, a map, or a thick card, the weight goes up. Large envelopes, over a certain size, are classed as large letters and need more postage. The safest way is to take one fully assembled invitation to your local Post Office and ask them to weigh it. They will tell you the exact postage needed. You can also check online, but the Post Office counter is reliable. Remember that square envelopes are often classed as large and may cost more. If you are sending abroad, international postage rates apply and are higher. Always buy a few extra stamps in case you need to send a replacement or a late invitation.