Postal boxes. Make the size count.
Choose postal and mailing boxes by usable space, the way they close and the size of the finished parcel.
What is a postal box?
Postal boxes are boxes used to send items through the post. Suppliers also use names such as mailing box, mailer and letterbox box for different shapes and closures. Compare the specification rather than relying on the name.
Match the box to your order
- Flat items: check usable depth once any lining or protective material is included.
- Several small products: plan how they sit together and stay separated where needed.
- Repeat online orders: test the assembly and closure with the real contents, then keep the specification.
Fold-over lids, tuck-in flaps and adhesive closures work differently. Check the supplied assembly instructions and whether extra tape or an insert is needed. No particular closure style is confirmed for our first range yet.
Does “letterbox box” mean a Royal Mail Large Letter?
No. A descriptive product name does not establish the postage format. Check the packed external dimensions, total weight, contents and rules for the service you are buying. A box may also bulge once filled.
Use the postal box size guide for the measurements to take and links to Royal Mail’s own guidance. No Box Supply Co. product has yet been assigned to a postal price category.
How much internal space do I need?
Measure the item together with the protection you intend to use. Check how much space is available around folded flaps or inserts, and close a sample before committing to a regular pack. For a simple rectangular arrangement, start with our box size calculator.
Compare the whole pack
Check the number of boxes, whether inserts or protective materials are included and the delivered cost. For larger or heavier orders, compare the actual specifications of shipping boxes as well.