--- product_id: 46287045 title: "500 #9 INVOICE Envelopes by Sigma Source 3-7/8\" x 8-7/8\" Double Window Security Tint for QuickBooks, Computer Generated Invoices, Billing Statements and Legal Documents (Not For Quickbooks CHECKS)" brand: "sigma source" price: "£11.06" currency: GBP in_stock: false reviews_count: 8 url: https://www.desertcart.co.uk/products/46287045-500-9-invoice-envelopes-by-sigma-source-3-7-8 store_origin: GB region: United Kingdom --- # 500 #9 INVOICE Envelopes by Sigma Source 3-7/8" x 8-7/8" Double Window Security Tint for QuickBooks, Computer Generated Invoices, Billing Statements and Legal Documents (Not For Quickbooks CHECKS) **Brand:** sigma source **Price:** £11.06 **Availability:** ❌ Out of Stock ## Quick Answers - **What is this?** 500 #9 INVOICE Envelopes by Sigma Source 3-7/8" x 8-7/8" Double Window Security Tint for QuickBooks, Computer Generated Invoices, Billing Statements and Legal Documents (Not For Quickbooks CHECKS) by sigma source - **How much does it cost?** £11.06 with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/46287045-500-9-invoice-envelopes-by-sigma-source-3-7-8) ## Best For - sigma source enthusiasts ## Why This Product - Trusted sigma source brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Description Sigma Source Double Window Invoice Envelopes: Our envelopes are packaged in 500 pieces per box and is designed for: QuickBooks Invoices Business Billing Statements Legal Documents Key Features and Characteristics: Size: 3-7/8" x 8-7/8" – just the right size for your QuickBooks Invoices Easy Peel and Self-Seal - with good Adhesion and it easily shows if Envelope is tampered. Inside of Envelope is Blue Checkered Design - for Confidentiality, preventing content from showing or someone peeking! Color is White and is made with 24 LB Premium Smooth/Woven paper - envelope is strong (not flimsy or cheap) If you are LOOKING for High Quality Business, Invoice Envelopes that saves you time and stays intact during transport, Sigma Source Double Window Envelope is for you and most importantly, No Licking Required – just PEEL and SEAL. 100% Refundable if you are not completely SATISFIED! ## Features - DESIGNED FOR INVOICES AND BILLING STATEMENTS: Our #9 Invoice Envelope is designed for computer generated Invoices, QuickBooks Invoices, Billing Statements and Legal Documents. - EXCELLENT CONTENT PROTECTION: Security Tinted to make sure content stays confidential and protected. - PREMIUM QUALITY: Self Peel and Seal Flap with GREAT Adhesion; No Water or Licking Required! Just peel, press and you're done. Seal is excellent and long lasting. - SAVES TIME AND REDUCES COST: Double windows - no need to print or write on envelope. Self seal saves time and reduces cost - no liquid or licking required. - FEATURES: |Color - White|Texture - Smooth/Woven|Quantity - 500/box|Dimension - 3-7/8" x 8-7/8"| ## Images ![500 #9 INVOICE Envelopes by Sigma Source 3-7/8" x 8-7/8" Double Window Security Tint for QuickBooks, Computer Generated Invoices, Billing Statements and Legal Documents (Not For Quickbooks CHECKS) - Image 1](https://images-na.ssl-images-amazon.com/images/I/7178Y77o7uL.jpg) ![500 #9 INVOICE Envelopes by Sigma Source 3-7/8" x 8-7/8" Double Window Security Tint for QuickBooks, Computer Generated Invoices, Billing Statements and Legal Documents (Not For Quickbooks CHECKS) - Image 2](https://images-na.ssl-images-amazon.com/images/I/71MuECLxdXL.jpg) ![500 #9 INVOICE Envelopes by Sigma Source 3-7/8" x 8-7/8" Double Window Security Tint for QuickBooks, Computer Generated Invoices, Billing Statements and Legal Documents (Not For Quickbooks CHECKS) - Image 3](https://images-na.ssl-images-amazon.com/images/I/71T83EHxOPL.jpg) ![500 #9 INVOICE Envelopes by Sigma Source 3-7/8" x 8-7/8" Double Window Security Tint for QuickBooks, Computer Generated Invoices, Billing Statements and Legal Documents (Not For Quickbooks CHECKS) - Image 4](https://images-na.ssl-images-amazon.com/images/I/718ABS5MouL.jpg) ![500 #9 INVOICE Envelopes by Sigma Source 3-7/8" x 8-7/8" Double Window Security Tint for QuickBooks, Computer Generated Invoices, Billing Statements and Legal Documents (Not For Quickbooks CHECKS) - Image 5](https://images-na.ssl-images-amazon.com/images/I/7178Y77o7uL.jpg) ## Customer Reviews ### ⭐ These do not fit Quickbooks checks properly. The top ... *by C***A on Reviewed in the United States on September 27, 2017* These do not fit Quickbooks checks properly. The top left window is too tall making the payee name show up below the return address and the envelopes are too large so the check moves around. ### ⭐⭐⭐⭐⭐ Five Stars *by A***R on Reviewed in the United States on June 18, 2018* They hold my invoices, but they don't bring me coffee and scrambled eggs in the morning. ### ⭐⭐⭐⭐⭐ As expected A *by M***K on Reviewed in the United States on February 11, 2019* Great price --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.uk/products/46287045-500-9-invoice-envelopes-by-sigma-source-3-7-8](https://www.desertcart.co.uk/products/46287045-500-9-invoice-envelopes-by-sigma-source-3-7-8) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-05-17*