extra large postage boxes

extra large postage boxes are big postal cartons for bulky products, multi item orders and items that will not fit a standard shipping box. Custom Postal Boxes manufactures them in Wolverhampton in strong corrugated board, made to size and printed if required. Orders are quote based, with free design support, low minimum order quantities and free UK delivery.

What extra large postage boxes are used for

Large products create a different packing problem from small parcels. The item may be light but wide, like bedding, lampshades, artwork, toys and homeware, or heavy and dense, like equipment and bundled stock. In both cases a box that only just fits on paper can fail in practice, because staff need room to load the item, add edge protection and close the flaps without forcing them. Extra large sizes give that working room while keeping the parcel as one protected unit rather than several taped together boxes.

Common uses include furniture parts, garden items, sports goods, bulk clothing orders, exhibition materials and returns consolidation. Our Cardboard Shipping Boxes range covers the general shipping sizes, and extra large work usually starts from the item dimensions and the carrier you plan to use. Measure the item diagonally as well as by side, because wide flat items often enter a box more easily on a slight angle during loading, then settle flat for transit.

Sizes and carrier limits for extra large postage boxes

Carrier limits decide whether a large box travels as a normal parcel or needs a specialist service. Royal Mail medium parcels are limited to 610mm by 460mm by 460mm and 20kg on most services, as set out in the Royal Mail size and weight guidance, so anything larger moves to courier networks or Parcelforce style services with their own size rules. Check the length plus girth rules of your chosen carrier before ordering boxes, because a box can pass a simple length check and still breach a combined measurement limit.

Board strength for large panels

Wide panels flex more than small ones, so board grade matters more as box size grows. Double wall corrugated board stiffens the long sides, resists puncture from corners inside the load and holds a stack without the top panel sinking. Our Double Wall Shipping Boxes and Heavy Duty Shipping Boxes are the relevant strength options, and tape pattern matters too. Long flaps should be taped along the full seam, with extra strips across the ends where flap tension is highest.

Packing large and light items

Light bulky items damage differently from heavy goods. They dent, bend and crease rather than break, and they can be crushed by heavier parcels stacked above them. Keep the item away from the box walls with edge protectors or a fitted insert, mark the parcel clearly for careful handling, and avoid filling large voids with heavy fill that shifts to one end. A firm top layer under the flaps spreads stacking pressure across the whole parcel.

Ordering extra large boxes without waste

Oversizing has a cost. Large boxes take more storage space, use more board and can attract higher carrier charges based on size as well as weight. The answer is a box made to your item, large enough to pack safely and no larger. Supplied flat, even big cartons store in a compact stack, and ordering in sensible batches keeps warehouse space under control during peak periods.

Print can include handling guidance, this way up marks and your branding, which helps when parcels pass through several handlers. To brief the work, send item dimensions and packed weight for a quote and say which carrier will take the parcels. Pricing depends on size, material and quantity. If some items in the range are heavy as well as large, the specification notes in our custom heavy duty boxes guidance will help you choose the board grade.

FAQs about extra large postage boxes

What counts as an extra large postage box?

There is no single trade definition. It generally means a postal box larger than standard small and medium parcel sizes, used for bulky, wide or multi item orders. The working definition for your order is set by the size limits of the carrier you plan to use.

Can extra large boxes be sent with Royal Mail?

Only within Royal Mail parcel limits, which for medium parcels are 610mm by 460mm by 460mm and up to 20kg on most services. Larger or heavier parcels need a courier service, so check the limits before the box size is finalised.

What board is best for a very large box?

Double wall corrugated board is usually the safer choice because wide panels flex more and need the extra stiffness and puncture resistance. Heavy loads, stacking and long routes all push the specification towards double wall board.

How can I keep postage costs down on large parcels?

Make the box to the item size, avoid spare volume, keep the packed weight accurate and check carrier size bands before ordering. A smaller, stronger box usually travels better and costs less than a larger weak box filled with void fill.