Best Large Letter Box Mailers of 2025

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Large Letter Box Mailers are a great solution for businesses and individuals who need to send items through the post without incurring the higher costs of sending a parcel. These mailers are designed to fit through a standard letterbox, making them a convenient and cost-effective option for sending items such as books, DVDs, and small gifts. Made from high-quality materials, they offer protection for your items during transit and are available in a range of sizes to suit your needs. Whether you're sending a single item or a larger quantity, Large Letter Box Mailers are an excellent choice that will help you save money and get your items to their destination safely.
At a Glance: Our Top Picks
Top 10 Large Letter Box Mailers
100 Large Letter Boxes by MEG4TEC
The MEG4TEC Large Letter Boxes are designed to meet your mailing needs with convenience and reliability. Each box has an external size of 235mm x 165mm x 22mm, making it perfect for large letter shipping. With an internal size of 225mm x 160mm x 20mm, you can easily fit various items securely inside. Weighing only 35g, these boxes are lightweight, which can help reduce postage costs. Made from sturdy 1mm thick single wall cardboard, they provide excellent protection for your contents during transit.
150 Large Letter Box Shipping Mailers
The MEG4TEC Mail Postal Boxes are designed for efficient shipping with their external dimensions of 235mm x 165mm x 22mm, making them suitable for large letter qualifications. The internal size of 225mm x 160mm x 20mm provides ample space for your items while keeping them protected. Each box weighs just 35g, ensuring that your postage costs remain low. Made from sturdy 1mm thick single wall cardboard, these boxes offer excellent durability, giving you peace of mind that your items will arrive safely at their destination.
AKAR Large Letter Postal Boxes Pack of 50
The AKAR Postal Boxes are ideal for sending fragile items securely, thanks to their robust single-wall corrugated cardboard construction. These large letter postal boxes are lightweight yet sturdy, ensuring your items are well-protected during transit. With a convenient locking tab, you can easily secure your package, making them perfect for gifts or retail items. Plus, they are stackable and quick to assemble, saving you time and effort when preparing your shipments.
AKAR C5 A5 Large Letter Postal Boxes
The AKAR Postal Boxes are ideal for shipping fragile items securely. Made from durable single-wall corrugated cardboard, they ensure your belongings remain safe during transit. Their lightweight design makes them easy to handle, while the locking tab allows for secure closure. These versatile boxes are perfect for gifts, stationery, or e-commerce shipping, providing a practical solution for all your mailing needs.
MEG4TEC 200 Pack C5 A5 Postal Boxes
The MEG4TEC Postal Boxes are an excellent solution for your mailing needs. With a pack of 200 strong cardboard boxes designed for large letters, they measure 235mm x 165mm externally and 225mm x 160mm internally. Their 1mm thick cardboard ensures durability, protecting your items during transit. You will appreciate how quick and easy they are to assemble, making your packing process hassle-free. Plus, these boxes are sealable with clear or brown tape made from recycled material, promoting sustainability while you ship.
50 Pack PIP Box Shipping Mailers
The PIP Box Mailers come in a convenient pack of 50, perfect for your shipping needs. With external dimensions of 235mm x 165mm x 22mm, they qualify as large letter boxes, making them ideal for mailing various items. The sturdy 1mm thick single wall cardboard ensures your packages are well-protected during transit. Additionally, these mailers are quick and easy to assemble, allowing you to save time on packing. You can seal them securely with clear or brown tape made from recycled material, contributing to an eco-friendly packaging solution.
AKAR A6 Large Letter Postal Box Pack
The AKAR Postal Box is perfect for sending fragile items safely. Made from durable, recyclable cardboard, these boxes ensure your items remain secure during transit. Their lightweight yet sturdy design makes them ideal for various uses, from shipping products to gift packaging. You will appreciate the locking tab feature, which secures the contents effectively, and the ease of assembly, as no tape or glue is required. These boxes are designed for convenience and reliability in all your mailing needs.
Large Letter Cardboard Shipping Boxes by SR Mailing
The SR Mailing C4 Postal Boxes are designed for your shipping needs. Made from robust 1.2mm thick single wall cardboard, they ensure your items are well-protected during transit. Each box is delivered flat-packed and securely wrapped, making storage easy and convenient. You will appreciate how quick and easy they are to assemble, allowing you to prepare your parcels in no time. With a size qualifying for large letter postage, these boxes are perfect for sending documents and other flat items efficiently.
AKAR C6 Large Letter Postal Boxes - Pack of 50
The AKAR C6 Postal Boxes are ideal for shipping fragile items safely. Made from durable, lightweight corrugated cardboard, these boxes ensure your items remain secure during transit. They feature a convenient locking tab for easy closure, allowing you to send gifts or stationery without worry. With a flatpack design, these boxes are easy to assemble, saving you time and effort when preparing your parcels. Recyclable and strong, they provide excellent protection compared to standard mailers.
SmithPackaging C6 Brown Cardboard Postal Boxes
The SmithPackaging C6 Boxes are ideal for sending items securely. This pack contains 50 large letter boxes, allowing you to ship multiple items efficiently. Made from durable single wall corrugated cardboard, they ensure your contents are well protected during transit. Being 100% recyclable, you can feel good about your environmental impact. These boxes are also compliant with Royal Mail standards, making them a convenient choice for all your mailing needs.
Frequently Asked Questions (FAQs)
1. Can I post box large letter?
The maximum Parcel size allowed into our new Postboxes is 44cm x 35cm x 16cm. Any Royal Mail Special Delivery Guaranteed items, Royal Mail International Tracked items, and any Royal Mail Tracked Returns without a barcode on the label must be posted in a Post Office branch and cannot be dropped off at a Parcel Postbox.
2. What size is a large letter box?
The Royal Mail large letter size was introduced in 2006 as part of the new Pricing in Proportion (PiP) policy. A large letter's size can be no larger than 353 x 250 x 25mm (a normal letter can be only up to 240 x 165 x 5mm) with a maximum weight of 750g.
During our large letter box mailer research, we found 120 large letter box mailer products and shortlisted 10 quality products. We collected and analyzed 28,616 customer reviews through our big data system to write the large letter box mailers list. We found that most customers choose large letter box mailers with an average price of £15.94.
The large letter box mailers are available for purchase. We have researched hundreds of brands and picked the top brands of large letter box mailers, including AKAR, Other, Parcel Pack, SR Mailing, SmithPackaging. The seller of top 1 product has received honest feedback from 915 consumers with an average rating of 4.7.

Jordan Akthar owns one stationery store in Bradford, and another in Derby. He started with a corner bookshop, and now the rest is history. He is often found in his stores taking count of inventories of books and stationery. Jordan also likes to write, and this drove his passion for writing articles on stationery maintenance. He owns a blog, where in his free time, he would write DIY tips on how you can recycle and refine your stationeries.