mailer boxes

mailer boxes are folding corrugated boxes with a hinged lid and side wings that lock into place, designed to protect products through the post while looking smart enough to be the packaging the customer opens first. They have become the standard choice for ecommerce, subscription and gift brands because they assemble quickly, close securely and print beautifully. Custom Postal Boxes makes mailer boxes in Wolverhampton in custom sizes, with low minimum order quantities, free design support, free UK delivery and quote based pricing.

How mailer boxes are constructed

A mailer box is cut from one sheet of corrugated board, usually a fine E flute profile that balances strength with a smooth print surface. The base folds up, the side wings tuck in to lock the corners, and the lid closes over the front with a tab that slots into the base wall. Many designs add a self seal adhesive strip so the lid is pressed shut without tape, and a tear strip so the customer opens the parcel cleanly without scissors or a torn lid. Because the corners are double layered where the wings fold, the finished box resists crushing at exactly the points where parcels are dropped and stacked in transit.

What mailer boxes carry best

Clothing is a natural fit, since folded garments are light, flat and easily creased in a bag but stay crisp in a box. Cosmetics, skincare, candles, stationery, jewellery, snacks and small home goods all suit the format, as do curated sets where several items must arrive arranged rather than jumbled. Subscription brands lean on mailer boxes because the same box works every month and the inside of the lid is a reliable place for the message that changes with each edition. Very heavy or sharp edged goods are better in a shipping carton, where thicker board and taped seams carry the load more safely.

Inserts that hold products in place

An insert turns a good mailer into a precise one. A simple card platform with cut outs keeps bottles upright, a divider keeps a set separated, and a snug tray stops a hero product sliding into the corners. Tissue and shredded paper add cushioning and colour but should support the insert rather than replace it, because loose fill settles in transit and leaves the top items free to move. When you brief an insert, list every item in the box with its size, including samples and leaflets, because the smallest extra is usually the piece that ends up loose and rattling.

Choosing sizes for mailer boxes

Size the box from the arranged contents, not from the single largest item, and allow a modest margin for tissue and inserts. Then check the closed box against the postal band you intend to use. The Royal Mail size guidance places small parcels at up to 450 mm by 350 mm by 160 mm and 2 kg, with medium parcels up to 610 mm by 460 mm by 460 mm and 20 kg. Most mailer boxes live comfortably in the small parcel band. A box a few millimetres too deep for its band costs more to post on every single order, so confirm the external dimensions with tape and lid closed before artwork is finalised and quantities are printed.

Print and finish options that suit mailer boxes

Mailer boxes accept print on the outside, the inside or both, and the inside of the lid is the most read panel in the whole pack. White board carries full colour artwork crisply, kraft board offers a natural surface where one or two colours look confident, and black board creates contrast for premium ranges. Matt lamination keeps colours calm, gloss makes them vivid, and spot finishes can pick out a logo without printing the whole box in a costly special process.

Ordering mailer boxes from Custom Postal Boxes

Browse the breadth of the format in our custom mailer boxes UK range, the practical cardboard mailer boxes and the cushioned structure of corrugated mailer boxes, all within the wider custom mailer boxes category. Low minimum order quantities let new brands test a design on real orders before committing to volume, and free design support helps you place artwork correctly across the lid, walls and insert. When you are ready, get a quote through our contact page with your product sizes, chosen board and quantity.

FAQs about mailer boxes

Do mailer boxes need tape to close?

Many designs close securely with a locking tab alone, and versions with a self seal strip press shut without any tape at all. Tape is still worth adding for heavier contents or long journeys, where an extra seal guards against the lid being forced in handling.

What board are mailer boxes made from?

They are usually made from E flute corrugated board, which is slim, strong and smooth enough for quality print. Heavier products can move to a stronger flute profile, and the choice should follow the packed weight and how the parcels will be stacked in transit.

Can mailer boxes be used for subscription services?

Yes, and they are one of the most popular formats for subscriptions. A consistent box with changeable inside lid messaging, inserts matched to each edition and space for samples lets the packaging stay familiar while the contents change every month.

Are mailer boxes recyclable?

Corrugated cardboard mailer boxes can be flattened and recycled through normal cardboard collections. Removing tape and any non cardboard extras before recycling helps the material move through the recycling process cleanly and is a simple instruction to print inside the lid.