A9 Envelope Postage
An A9 envelope is 5 3/4 x 8 3/4 in and fits a 5 1/2 x 8 1/2 half-letter card. It is a standard letter, starting at $0.82 for 1 oz.
Your answer
Standard letter
No extra postageRegular letter postage. No surcharge.
- Postage per piece
- $0.82
- 100 invitations
- $82.00
Stamps for each one
1 × Forever (1 oz letter)
Why
- This is a standard letter: within 6.125 x 11.5 in, no thicker than 0.25 in, and length divided by height is 1.52 (it must be between 1.3 and 2.5). USPS rule
Rates last verified on
100 invitations: $82.00 in postage ($0.82 each, standard letter)
Half a letter sheet, mailed flat
A9 is the envelope for anything made from a letter sheet cut or folded in half: ceremony programs, large announcements, folded invitations printed at home. Its length divided by height is 1.52, right in the middle of the allowed range, so it is one of the most forgiving shapes there is.
It is also inside the letter size limit with room to spare: 5 3/4 in high against a 6 1/8 in maximum, and 8 3/4 in long against 11 1/2 in.
Bigger paper crosses 1 oz sooner
A half-letter card has about a third more area than a 5 x 7, and the envelope is larger too. The same card stock that keeps a 5 x 7 under 1 oz can put an A9 over it. A folded card doubles the paper again.
So assume nothing: weigh one finished piece. Under 1 oz is $0.82; anything from just over 1 oz to 2 oz is $1.11.
The thin-piece rule
One rule only bites on larger envelopes. A piece over 6 in long or 4 1/4 in high must be at least 0.009 in thick, or it is nonmachinable. An envelope with a card in it is always thicker than that. A single unfolded sheet of light paper sealed in an A9 might not be.
Do not use it for a 5 x 7 card
An A9 is sometimes bought as a roomy envelope for a 5 x 7 invitation. It works, but the card slides around and the extra paper is weight you pay for. If the suite is close to an ounce line, the smaller A7 is the safer envelope.
Addressed along its 5 3/4 in side, an A9 is still mailable but reads as a ratio of 0.66 and pays the $0.49 surcharge.
Compare the options
| Option | Mail class | Each | For 100 |
|---|---|---|---|
| A9, 1 oz | Standard letter | $0.82 | $82.00 |
| A9, 1.4 oz folded card | Standard letter | $1.11 | $111.00 |
| A7 with a 5 x 7 card, 1 oz | Standard letter | $0.82 | $82.00 |
| A9 addressed along the short side | Nonmachinable letter | $1.31 | $131.00 |
Questions and answers
How much postage does an A9 envelope need?
$0.82 up to 1 oz and $1.11 up to 2 oz. Its size never adds a surcharge.
Is an A9 envelope a letter or a large envelope?
A letter. It is under the 6 1/8 x 11 1/2 in letter limit in both directions.
What size card goes in an A9 envelope?
A 5 1/2 x 8 1/2 in card, which is a US letter sheet cut or folded in half.