30cm postage box

A 30cm postage box is a postal carton with at least one side measuring 30cm, used to send compact products safely through UK delivery networks. At Custom Postal Boxes we make each 30cm postage box to order in Wolverhampton, so the other two dimensions, the board grade and the print are chosen around your product rather than forcing your product into a stock size.

What a 30cm postage box can hold

Thirty centimetres is a useful working length for many everyday orders. It suits folded clothing, small homeware, craft kits, boxed cosmetics, paperback sets, cables and accessories, and smaller electrical goods once they are cushioned. The honest check is always all three measurements together. Measure your product at its widest points, add room for protective wrap, and then choose the internal length, width and depth of the box. A close fit limits movement, reduces the filler you need and presents the order neatly when the lid or flaps are opened.

Think about stacking too. Orders rarely travel alone, so the box needs walls that hold their shape when other parcels sit on top. Corrugated cardboard is the usual choice at this size because its fluted middle layer absorbs knocks while the flat outer layers give a clean surface for print and labels. For lighter contents a single wall board is often enough, while heavier or more fragile items may justify a stronger grade.

Postage bands and the 30cm postage box

A 30cm side does not by itself decide your postage band, because carriers price on the finished parcel as a whole. Royal Mail publishes its format limits openly, and its Royal Mail size and service guidance lists a small parcel as up to 45cm by 35cm by 16cm and up to 2kg. A box measuring 30cm by 30cm by 30cm therefore falls outside the small parcel depth limit even though its length looks modest, and it would travel as a larger parcel. A flatter box such as 30cm by 25cm by 12cm can stay within small parcel limits if the packed weight also stays within the band.

Measuring before you order

Measure the packed product, not the empty shelf item. Include caps, handles, booklets and any inner wrap, because those details decide whether the lid closes without bulging. Bulging sides can push a parcel into a higher band and they also weaken the corners that do most of the protective work.

A simple fit test

Make a quick mock up from scrap card at your intended internal size, pack the product exactly as a customer would receive it, and weigh the finished parcel on kitchen scales. If it packs calmly, closes flat and stays within your chosen band, the size is ready to brief. If you need a ready made starting point, compare our small postage boxes and our cardboard postal boxes before you settle on dimensions.

Print, board and packing choices

Print turns a plain carton into packaging your customers recognise before they read the label. You can print your logo and brand colours on the outside, add handling notes or a short message inside, and keep the label area clear so barcodes scan first time. Natural brown kraft board gives a warm, honest look and prints bold single colours well, while white board gives brighter colour reproduction for detailed artwork. The related range of kraft mailer boxes shows how the same thinking applies to flatter mailer styles.

Pack with purpose. Wrap fragile items individually, fill any remaining void with paper based filler so contents cannot slide, and seal every seam with strong tape. For heavier loads, our custom shipping boxes give a stronger route. Pricing for every order depends on size, material and quantity, and we offer low minimum order quantities, free design support and free UK delivery. Request a tailored price through our contact page for a quote.

FAQs about 30cm postage box

What products suit a 30cm postage box?

Clothing, craft kits, small homeware, boxed toiletries, books and compact electrical goods all suit this size well. The product should sit inside with room for wrap on every side and the lid or flaps should close without forcing or bulging.

Does a 30cm postage box count as a Royal Mail small parcel?

Only if the other dimensions and the packed weight also fit the small parcel limits of 45cm by 35cm by 16cm and up to 2kg. A cube shaped box with 30cm depth is too deep for that band, so always check all three sides.

Can I have my logo printed on the box?

Yes. Your logo, brand colours and messages can be printed outside and inside the box. Free design support is included, so artwork is checked for position and legibility before production begins.

How many boxes do I need to order?

Low minimum order quantities are available, which suits new ranges and seasonal products. Share your product size and the quantity you have in mind when you request a quote and the price will reflect that exact specification.

What board should I choose for heavier items?

Choose a stronger corrugated grade when the contents are heavy, sharp edged or fragile. Tell us the packed weight and how the parcels will travel, and we will recommend a board that protects without adding needless bulk.