Prepaid envelopes, also known as postage paid envelopes, are an easy and convenient way to send something back to someone. If you are the receiver of the prepaid envelope, you will save money on postage by using it.
A prepaid envelope is an envelope that already has postage paid on it. There will either be stamps already attached or a square in the upper right hand corner, where the stamp should go, that identifies it as postage paid or prepaid.
All you need to do to use a prepaid envelope is place your piece of mail in the envelope, seal the envelope and then put it in a mailbox for the postman to pick up. You are not required to pay any postage.
Prepaid envelops are often used for various types of mail. They can be sent to you from a business or someone you know. People use these types of envelopes because they want you to return something to them and they want to remove all possible barriers, including postage costs.