SIZE REQUIREMENTS
Only letter or postcard sizes are acceptable.
Each letter size piece must meet the following size requirements:
A. The length must be at least 5 inches and not more than 11 1/2 inches.
B. The height must be at least 3 1/2 inches and not more than 6 1/8 inches.
C. The thickness must be at least 0.007 inch and not more than 1/4 inch.
D. The length divided by the height must fall between 1.3 and 2.5.

POSTCARDS
Each business reply card must meet the following size requirements:
A. The length must be at least 5 inches long and not more than 6 inches long.
B. The height must be at least 3 1/2 inches and not more than 4 1/4 inches high.
C. The thickness must be at least 0.007 inch and not more than .0095 inch.
D. The length divided by the height must fall between 1.3 and 2.5.

ADDITIONAL PHYSICAL REQUIREMENTS
Self-Mailers: Self-mailers prepared under the BRMAS system must be fabricated from paper having a minimum basis weight of 20 pounds, (using a 17 inch by 22 inch sheet size for 500 sheets) include instructions for folding and sealing (no staples allowed) in addition to meeting all other requirements for Business Reply Mail.
Cards: Business reply cards prepared under the BRMAS system must be printed on paper stock with a minimum basis weight of 75 pounds for 500 sheets measuring 25 inches by 38 inches, and have a thickness of at least 0.007 inch and not more than 0.0095 inch.

ADDITIONAL INFORMATION
Non-Standard Pieces:
Letters weighing 1 ounce or less that exceed the maximum size will be assessed a surcharge.
Mailpieces over 1 ounce will be weighed and charged the applicable rate.
Postcards exceeding the maximum size or thickness will be charged the 1 ounce letter rate.

Window Reply Envelopes:
The endorsement "NO POSTAGE NECESSARY...", horizontal bars, FIM, "BUSINESS REPLY MAIL" box must be printed on the address side of the envelope. Other required format elements must appear on the enclosure in the window or be printed on the envelope.
There must be at least a 1/8" clearance and no extraneous (non-address) printing around the edges of the address shown in the window and the window edge.
The window must be positioned no lower than 5/8" from the bottom edge of the envelope, and the address, as it appears inside the envelope, must be at least 1" from the left or right edge of the envelope.
Materials covering windows must allow the address to be readable.