Cardboard Boxes

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Postal Boxes

Flat pack cardboard postal boxes in Royal Mail PiP sizes. Large letter and small parcel options from Small (101 x 101 x 20mm) up to Maxi (420 x 340 x 73mm). Ideal for e-commerce, subscription boxes and small item despatch.

E-Commerce Crash Lock Boxes

One-piece cardboard boxes with an integrated crash lock base that pops into shape without tape. Available in 8 sizes from 110 x 100 x 70mm up to 426 x 300 x 300mm. Designed for fast, high volume e-commerce fulfilment.

Book Wraps

Wraparound cardboard mailers for shipping books, magazines, vinyl records and other flat, rigid items. Available in three sizes from 220 x 154 x 50mm up to 325 x 250 x 80mm. Strong, secure protection that resists bending in transit.

Choosing the Right Box for Despatch

The right packaging box depends on what you are sending, how it will travel through the postal or courier network, and how quickly you need to pack it. Here is a brief guide to help you choose:

For flat, lightweight items such as books, documents, clothing, phone cases and cosmetics, our Postal Boxes in Large Letter PiP sizes (Small, C6, DL, C5 and C4) are the most economical choice. These are designed to pass through a standard letterbox and qualify for Royal Mail’s large letter rate, keeping your postage costs down.

For deeper items that do not fit within the large letter threshold, our postal boxes in Small Parcel PiP sizes (Mini, Midi and Maxi) provide a sturdy option that still qualifies for the small parcel rate. These are well suited to candles, cosmetics sets, books and small gifts.

For high volume e-commerce despatch where packing speed matters, our Crash Lock Boxes are the practical choice. The integrated base pops into shape in one movement, eliminating the need for tape on the bottom and significantly reducing packing time. Available in 8 sizes, they are popular with fulfilment centres, subscription box businesses and online retailers.

For mailing books, magazines and other flat, rigid items, Book Wraps provide a wraparound design that hugs the contents and resists bending in transit. They fold flat for storage, assemble in seconds and need only a single piece of tape to secure, making them efficient at higher despatch volumes.

For fragile or cylindrical items such as bottles, jars, candles and glassware, our dedicated Flexi-Hex® Packaging range offers plastic-free protective options that absorb impact and conform to the shape of the item.

Postal Boxes for Royal Mail PiP

Our Postal Boxes are sized to comply with Royal Mail’s Pricing in Proportion (PiP) guidelines, which means you only pay for the postal tier your item actually falls into. Using a correctly sized PiP box avoids overpaying on postage, which can make a meaningful difference over hundreds or thousands of orders.

We stock postal boxes in eight sizes, split across two Royal Mail tiers. The Large Letter sizes (Small, C6, DL, C5 and C4) are 20mm deep and suited to flat items. The Small Parcel sizes (Mini, Midi and Maxi) are deeper and hold bulkier products. All are supplied flat packed in boxes of 25 or 50 and are quick to assemble by hand without tape or glue.

Crash Lock Boxes for E-Commerce

Our Crash Lock Boxes are one-piece cardboard boxes with an integrated base that locks into position when the sides are pushed together. This removes the need to tape the bottom of the box, cutting packing time and reducing tape usage. The design also creates a cleaner, more professional finish on the inside of the box, which matters for brands that want a good unboxing experience.

We stock crash lock boxes in eight sizes, from the compact Box A (110 x 100 x 70mm) up to Box K (426 x 300 x 300mm). All sizes feature five eco credentials and are made from sustainably sourced cardboard. They are packed in quantities of 20, making them practical for businesses at all despatch volumes.

Book Wraps for Mailing Books

Our Book Wraps are wraparound cardboard mailers designed for shipping books, magazines, vinyl records and other flat, rigid items. The pre-scored design folds tightly around the contents, hugging the item to prevent movement and resist bending in transit. They are quick to assemble by hand and need only a single piece of tape to secure, making them efficient at higher despatch volumes.

We stock book wraps in three sizes: 220 x 154 x 50mm (packed in 50’s) for paperbacks and small hardbacks, 311 x 240 x 50mm (packed in 40’s) for larger books and magazines, and 325 x 250 x 80mm (packed in 50’s) for thicker hardbacks, photo books and bundled items. All are made from FSC or PEFC approved cardboard and are fully recyclable.

Recyclable, Sustainable Cardboard

All of our packaging boxes are made from recyclable cardboard sourced from FSC or PEFC approved suppliers. This means the raw materials come from responsibly managed forests and can be fully recycled after use through standard household or commercial cardboard recycling. For businesses that report on their environmental impact, our boxes provide a clear, auditable sustainable packaging choice.

Our crash lock boxes carry five eco credentials, and our postal boxes carry three or four, depending on the size. All boxes are supplied flat packed, which reduces storage space in your packing area and lowers the carbon footprint of delivery to your premises.

Why Buy Packaging Boxes from Forms Plus?

Forms Plus have supported businesses with their printing and packaging requirements since 1981. We stock a full range of cardboard packaging boxes,  available for same day despatch. Our pricing is competitive and transparent, with further discounts available on larger orders.

We also supply a full range of complementary products, including Flexi-Hex®, Mailing Bags, Padded Envelopes, Packing Tape, Labels and Documents Enclosed Wallets, so you can keep all of your despatch supplies in one order.

Contact Our Team if you would like help choosing the right box or quantity for your needs.

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