Your Cart is Empty

#9 Double Window Security Envelopes for Quickbooks Invoices, Self Seal, 500 Count

11 reviews

  • Durable and professional #9 business envelope for mailing invoices, statements, and other office mailing needs
  • Roomy enough for a return envelope to be included, so you can get paid faster
  • Low profile flap design creates a wide opening for easy and quick envelope stuffing 
  • Peel and seal flap is quick and easy to use without any need to lick or moisten the glue 
  • Dark security tint lining keeps your important documents securely concealed throughout transit


Frustrated by flip-and-seal envelopes sticking to other mail, or the yucky taste that comes with standard gummed seal envelopes? A peal-and-seal design is the answer, with no mess, no residual stickiness, and no need for moistening. A standard security envelope that’s ideal for everyday business use, our #9 mailer keeps your documents safe and secure behind the strong glue seal throughout transit and a dark security tint lining.

Made from a durable 24lb white wove paper, this envelope comes equipped with a low profile flap design, which makes it easy to fold and stuff up to 10 sheets of standard letter size paper inside with room for a #8 return envelope as well – so you can make it simpler than ever for your clients to quickly return payments to you.

It can also be used as a return envelope itself when sent inside a #10 envelope, making the #9 one of our most versatile envelope choices that’s simple enough for everyday letters and statements, yet professional and secure enough for even high-profile business communications.


#9 Double Window Security Envelopes for Quickbooks Invoices, Self Seal, 500 Count

Part #: BSS-92588-002

We stand behind our products completely. We understand that buying products online can sometimes be difficult because you cannot physically see what you are buying; however, if our product is not exactly what you are looking for or does not meet your expectations, then we welcome you to send them back anytime for a 100% refund. Click here for more information regarding refunds or returns >

Key Features:

  • #9 double window envelope
  • Dimensions: 8 7/8 inches X 3 7/8 inches
  • Security lining
  • 24lb white wove paper
  • Package quantity: 500 Count


  • This envelope is equipped with a self seal, which means it requires that you peel away the protective strip to reveal the glue. It does not require moistening, but cannot be used in a bulk mail machine. For envelopes that can be used in a mail machine, you’ll want to use a gummed seal envelope.
  • This envelope is not suitable for printing in a laser printer, as the heat will melt or warp the windows.
  • While this envelope will work with QuickBooks invoices, it is NOT suitable for sending QuickBooks checks, as check information will not line up properly in the windows. Please click here for envelopes suited for mailing QuickBooks checks.

Product Details:

  • Brand: Blue Summit Supplies
  • Part #: BSS-92588-002
  • Barcode: X001AZ4VOV
  • Package dimensions: 8.5 x 12 x 4.5 inches
  • Package weight: 5.6 pounds
Customer Reviews
4.9 Based on 11 Reviews
Write a Review

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

Filter Reviews:
Lisa M.
United States United States
Excellent services

Quick and Easy been using Blue Summit for a few years and always quick easy timely delivery

Richard P.
United States United States
They have worked in the past

These have worked well for me in the past of Quickbooks invoices. I am waiting for my order as the delivery service is having problems delivering them to the correct location. Huge problem with delivery, nothing wrong with the product!

Kathryn E.
United States United States
self stick

Hi, I find myself putting pieces of scotch tape at each end because the self stick doesn't go all the way to the end and leaves loose flaps. I have also noticed (definitely not all your products) that when I receive mail in similar envelopes that the ends are also frequently taped down. Other than that - Blue Summit is the best!

Anna C.
United States United States
Dependable/Great Customer Service

I've been reordering the same billing envelopes for a couple years now. So simple to re-order and quick delivery. The price has been consistent as well unlike the big office supply stores!

Bridget G.
United States United States

It was easy to purchase and receive the correct, quality product. Thanks!