The following size limits for First-class mail are listed below. We recommend you check your local post office for size and weight limits before committing to purchasing your invitations.

• Size: minimum is 3 1/2” x 5” for envelopes, cards, and self-mailers.
  
  
• Cards larger than 4 1/4” x 6” require First-class letter-rate postage.  Please note: orientation of the address label may affect eligibility for mailing.
  
  
• Nonstandard Surcharge: additional postage is required for First-class matter weighing one ounce or less that exceeds 11 ½” in length, 6 1/8” in height, or ¼” in thickness. The placement of the address determines which side of the piece is the length; therefore, if the piece is addressed so that the address is read across the short side of the piece, a postage surcharge may apply.