Custom No. 9 Reply Envelopes Our Reply 9 Envelopes, otherwise known as the #9 envelope, is small enough to fit into a standard No. 10 envelope. These printed No. 9 Envelopes are 3 7/8 x 8 7/8. When you mail out an invoice or statement to a client, include a address #9 envelope when you expect a payment in return.It is also used by charities, billing agencies and other business organizations for ordering or remitting applications. Your envelopes will be printed with your return address and 3 lines for the client to print their address. Would you like full color instead? Check out this full color #9 Reply Envelope!
