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About Large Letter Boxes
Large letter boxes offer a plastic-free, low-cost method of transporting small items through the post.
These boxes are made to fit Royal Mail’s large letter size rules, with a maximum size of 353mm x 250mm x 25mm and a weight limit of 750g. Be careful not to overfill them, as this can result in higher postage charges.
The perfect size for small eCommerce items like jewellery, clothing and handmade gifts as well as larger documents like catalogues or books, these lightweight boxes offer a snug fit to minimise internal movement and reduce the risk of damage to your products, especially when combined with bubble wrap.
Frequently Asked Questions
Which type of postal box should I choose?
Large letter boxes are ideal for smaller, flatter items that fit within Royal Mail’s large letter specifications, helping you save on postage while ensuring easy delivery through standard letter slots. Bigger postal boxes in small or medium parcel sizes can offer more space and sturdier protection, making them a better choice for bulkier or more fragile items that need extra security in transit.
At Kite Packaging, we offer a wide range of postal boxes compliant with Royal Mail's Pricing in Proportion guidelines. This includes brown postal boxes, which provide a classic, eco-friendly look, and white postal boxes, ideal for a clean, professional presentation, as well as custom designs.
Are cardboard boxes eco-friendly?
Yes, cardboard boxes are completely recyclable and biodegradable, making them an eco-friendly option when compared to bubble mailers, for example, which utilise single-use plastic. Our range of cardboard boxes at Kite Packaging is fully kerbside recyclable and each box features 60-90% recycled content.
Why should I buy euro slot hang tabs with large letter postal boxes?
Our large letter postal boxes can be combined with paper euro slot hang tabs, which make it easy to create attractive product displays—great for retail stores, trade shows, and warehouses. Made from recyclable kraft material, these eco-friendly hangers come in rolls of 1000.
Make sure to check the euro hooks with your products and packaging to determine their exact weight-bearing capacity.
Can I post a large letter box through a letterbox?
Yes, you can post a large letter through a standard letterbox.
What size is a large letter box?
The dimensions for a large letter postage box are as follows: a length of 35.3cm (approx. 13.9 inches), width of 25cm, and a thickness of 2.5cm. The maximum weight a large letter postal box can hold is 750g.
These dimensions are subject to change, so it is always a good idea to check Royal Mail’s official website for the most up-to-date information regarding their packaging and sizing guidelines.
Can a large letter be cardboard?
A large letter postage box can be made of cardboard or any other suitable material so long as it meets the size and weight parameters set out by Royal Mail. If your cardboard packaging or envelope fits within their size and weight restrictions, it will be classed and shipped as a large letter package.