Ecommerce Postal Boxes

Crash lock ecommerce postal boxes for UK online retailers, subscription brands and fulfilment operations. Also sold as e-commerce boxes, ecommerce mailing boxes, ecommerce shipping boxes or postal mailers. Made on our own corrugated plant, supplied flat in trade packs. Browse all postal boxes, or FEFCO 0427 shipping boxes for standard postal formats.

The crash lock base, and what it's actually worth

Most postal boxes are one flat sheet you fold into shape — bend the base, tuck the flaps, seal the lid. Perhaps twelve seconds once you're practised.

A crash lock base arrives with the bottom pre-glued. You open the box out and the base locks itself flat in a single movement. No folding, no tucking, no tape underneath.

Three or four seconds per box. On its own that sounds like nothing. Across a thousand parcels a week it is roughly two hours of labour, every week, for a packaging cost difference of pennies.

That's the whole argument, and it only applies if you pack in volume. If you send a handful of parcels a day, a standard one-piece box is cheaper and does the same job — that's our FEFCO 0427 postal box range, and we'd rather you bought the right one.

The lid closes with a peel-and-seal adhesive strip, so a packed box needs no tape at either end.

Postage: these are parcels, not Large Letters

Worth being blunt, because it's the single most expensive assumption in ecommerce packaging.

None of these boxes qualify for Royal Mail Large Letter. That band caps at 25mm deep, and the shallowest box in this range is 50mm. A depth-boxed product is a parcel, and no packaging choice changes that.

They post as Royal Mail Small Parcel — 45 × 35 × 16cm, up to 2kg — with the largest sizes in Medium Parcel territory. Check the table and the current carrier limits before you standardise.

If Large Letter rates are what you need, your product has to be under 25mm packed, and that means a letterbox box rather than a depth box. It's a different format for a different product, not a smaller version of this one.

Choosing a size

Footprints and pack quantities are in the table below. Two things decide it.

Measure the product, not the old box. The commonest mistake in ecommerce packaging is inheriting a box size from a previous supplier and never rechecking it. Couriers price on volumetric weight — length × width × height divided by a divisor — so a box that's 30mm too deep across ten thousand parcels is a five-figure mistake.

Depth is the expensive dimension. Reducing depth cuts volumetric weight fastest and moves you down bands soonest. Cube boxes suit awkward or multi-item orders; shallow footprints suit anything flat.

Who these suit

• Online retailers shipping daily from a packing bench
• Subscription brands with a fixed monthly product
• 3PL and fulfilment operations where seconds per parcel compound
• Marketplace sellers on Amazon, eBay and Etsy
• Health, beauty and supplement brands
• Anyone hand-packing more than a few hundred parcels a week

Why buy from us

We're part of a manufacturing group and the board in these boxes is made in-house rather than bought in and marked up — there's no middleman margin in the price. Making our own board also means the specification is negotiable: if you need a footprint we don't stock, or a printed outer, that's a quote rather than a no.

Behind the range sits over 100,000 square feet of warehousing, which matters more on this product than most. An ecommerce operation that standardises on one box size cannot afford it to be on back-order in November.

Practical detail

Micro-flute corrugated, supplied flat with the base pre-glued, and a peel-and-seal lid for tape-free closure. The kraft surface takes labels, barcodes and direct print cleanly — on a subscription product the box is the first thing the customer sees every month, and printing it is one of the cheapest brand investments available.

Fully recyclable in normal household paper collection, with no plastic tape needed to close it.

Not sure which size fits your product? Send us the dimensions and we'll work through the volumetric maths with you.

Delivery and returns

Order by 2pm, Monday to Friday, for same-day dispatch. Free UK mainland delivery in 1–2 working days, with a £75 minimum order. Full terms on our delivery and returns pages.