Can I mail handmade envelopes through USPS?

Yes. USPS accepts handmade envelopes as long as they meet the same size, shape, and legibility rules as any other mail piece.

• Minimum size: 3.5" x 5".
• Maximum size for standard letter rate: 6.125" x 11.5".
• Shape: must be rectangular. Square or irregular envelopes may need extra postage.
• Address area: the recipient address has to be clearly legible with room for a barcode.
• Thickness: stay under 1/4 inch to keep the letter rate.

Envelopes that fall outside these limits still mail, they just cost more. Design inside the window and you keep the lowest postage. For a mailing where every envelope has to meet spec, factory-printed envelopes guarantee consistent dimensions.