Does Square Envelopes Require More Postage?

Square envelopes will cost you an extra $0.30 per letter in addition to the postage required for the weight and dimensions of your envelope. For 1 oz letters this means you'll need a $0.88 stamp (instead of a $0.58 stamp) and for wedding invitations that weigh 2oz you'll need a $1.08 stamp (instead of a $0.78 stamp).

Can I use 2 Forever Stamps on a square envelope?

Can I use 2 Forever stamps for extra postage? You can use more than one stamp forever if you want to send a package or letter that weighs more than an ounce. Each stamp is worth the current premium rate (not what you paid for it).

How many stamps do I need for a square envelope?

As of January 24, 2021, If you are mailing a square envelope that weighs less than 1 oz., or a rectangular envelope that weighs between 1-2 oz. (most wedding invitations) domestically, you will need 75¢ worth of postage, or 1 2-ounce “forever” stamp.