I didn't put enough stamps on my letter. How do I rectify the error?

You need stamps to send a letter. How many and which stamps depend on the size (standardised or non-standardised), weight and destination of your letter. Quickly find how many stamps your letter requires via our overview page. You can calculate the price of your letter at the same time. To the overview page

The number of stamps you attach to your letter depends on:

• the destination
• the size and weight of your letter

Quickly find how many stamps your letter requires via our overview page. You can calculate the price of your letter at the same time.

Stamps with a face value in Belgian francs will be invalid from 1 January 2028. Stamps with a face value in euros are valid indefinitely. You can use them to frank

• Non prior mail in Belgium.
• Mail for foreign addresses. In this case, affix a blue A Prior sticker as well.

The old stamps cannot be used for prior mail in Belgium (this requires a prior stamp with barcode). Parcels or registered mail cannot be franked with the old stamps either.