custom size mailing boxes

custom size mailing boxes are postal boxes manufactured to the exact internal length, width and depth your products require, instead of the nearest stock size off a shelf. Custom Postal Boxes makes custom size mailing boxes in Wolverhampton in corrugated board matched to the weight of the contents, with low minimum order quantities, free design support and free UK delivery. A box that fits properly protects better, needs less filling and keeps postage under control on every order.

When custom size mailing boxes beat stock sizes

Stock boxes work when a product happens to match them. The problems start when staff are folding tissue into empty corners, taping down lids that bulge, or watching fragile items slide inside a box that is nearly right. Unusual shapes suffer most: long, flat, tall and mixed product sets rarely suit standard dimensions. If you find the same packing compromise repeated every day, the box is the wrong size, and a made to measure format removes the compromise at its source.

How to measure for an exact fit

Measure the product as it will travel, wrapped and with any accessories included, then record internal length, width and depth in millimetres. Allow a few millimetres of clearance so the item slides in without force and the lid closes flat, and add space for an insert if the contents are fragile. If several products ship together, measure the full set arranged as it will be packed, not each piece on its own.

Allowing for inserts and wrapping

A shaped insert, tissue or a protective sleeve all take up room that a bare product measurement misses. Pack a trial set exactly as a customer would receive it, weigh it and measure it again before you confirm the box size. Our custom mailing boxes made to your dimensions and cardboard mailer boxes for everyday orders both start from that packed measurement.

Postage bands reward a close fit

Carriers price parcels by size bands as well as weight, so empty space can cost money twice: once in filler and once in postage. Royal Mail, for example, sets a small parcel limit of 450 mm by 350 mm by 160 mm with a weight limit of 2 kg, and a medium parcel limit of 610 mm by 460 mm by 460 mm up to 20 kg. A box designed a few millimetres smaller can keep a product in the lower band for its whole life. Check the current figures on the Royal Mail Tracked 24 page with size and weight limits before you fix your dimensions.

Board grade follows the contents

Size is only half of the specification. Light board suits clothing and paper goods, while heavier or fragile contents need stronger corrugated grades or a double wall construction like our custom shipping boxes for heavier goods. Tell us how the parcels travel, by post, courier or pallet, and how they are handled, because a box that is stacked in a van needs more compression strength than one posted singly.

Ordering custom size mailing boxes

Send the packed measurements of your product, its weight and an idea of monthly volume. Pricing depends on size, material and quantity, so a quote is prepared for your exact specification rather than a list price. Low minimum order quantities make it sensible to start with your best selling line, prove the fit at the packing bench and then extend exact sizes across the range. Request your quote on the contact page and free design support will help with print if you want the box branded as well as fitted.

custom size mailing boxes FAQs

How do I work out the size of mailing box I need?

Measure your product as it will be packed, including wrapping and inserts, in millimetres for length, width and depth. Add a small clearance so the lid closes without pressure, and use those figures as the internal dimensions of the box.

Will a custom size box reduce my postage costs?

It can, when a stock box pushes your parcel into a higher size band or needs heavy filler. A close fit keeps the parcel as small and light as the product allows, although the saving depends on your carrier and the band boundaries.

What is the smallest quantity I can order?

Low minimum order quantities apply, so a trial run for one product line is practical. Share your measurements and expected volume when you ask for a quote and the quantity can be set to suit a test or a full launch.

Can custom size mailing boxes be printed too?

Yes. A made to measure box can carry your logo, colours and messages inside and out, just like a standard printed mailer. Size and branding are agreed together so artwork is placed correctly on the finished panels.