Choose parcel packaging in four steps: establish which carrier size band the order should fall into, pick a format that sits comfortably inside it, specify restraint so the product cannot move during sortation, and specify a closure that will not fail. Choosing the format first and checking the band afterwards is how businesses end up overpaying on every order.
Band first, format second
The instinctive order is to choose a box that fits the product and then see what it costs to send. Reversing that order is worth real money, because parcel pricing is banded and the bands are published.
Decide which band a product group should ship in, then specify a format that sits comfortably inside it. If the product will not fit inside that band, you at least know the decision you are making rather than discovering it on an invoice.
Know your thresholds
Every carrier publishes size and weight thresholds, and they differ. The ones that matter most in practice are:
- Letterbox depth - the shallowest band, and the one that also avoids failed deliveries.
- Small parcel dimensions - usually the biggest single step up from letterbox.
- Maximum length and girth - exceeding these triggers surcharges rather than a band.
- Weight breaks - which interact with volumetric calculations.
If you use several carriers, specify to the tightest set so one format works everywhere. See postal and parcel packaging.
Match the format to the product group
| Product group | Format | Why |
|---|---|---|
| Flat, rigid-ish | Book wrap or wrap-around | Grips the product, often letterbox depth |
| Soft, non-fragile | Paper or polythene mailer | Light, cheap, no wasted volume |
| Small rigid | Postal box | Structure, stacks well in the network |
| Fragile | Carton with fitted insert | Restraint plus cushioning |
| Multi-item orders | Carton with partition | Stops items knocking together |
| Long or awkward | Tube or purpose-specified format | Avoids length surcharges |
Format selection for parcel delivery.
Restraint beats cushioning in a parcel network
A parcel goes through belts, chutes, tipping trays and several manual handlings. Over that journey, loose protection settles and the product finds room to move - and movement causes most parcel damage.
Something that physically holds the product still is more effective and usually cheaper per order than repeated handfuls of fill. See protective packaging.
Closure is the quiet failure
A pack that opens in sortation has failed as completely as one that was crushed, and closure is under-specified more often than any other element.
Specify the tape pattern rather than just the tape, match the tape construction to the board, and use a full overlap or crash-lock base for anything with weight. See custom printed tape.
Think about the return journey too
If your category has a meaningful return rate, the pack has a second job. A format the customer can re-close decides whether the returned item arrives back in resellable condition.
A tear strip with a second adhesive lip, plus printed instructions inside the lid, costs little and recovers margin. See returns management.
A short specification checklist
- Target carrier band identified for the product group.
- Format chosen to sit inside it, with the external dimensions checked.
- Restraint specified so the product cannot move.
- Closure specified - tape construction, pattern, base method.
- Re-closability decided, based on your actual return rate.
- Sample built and tested with the real product before rollout.
See parcel services for the despatch side and ecommerce packaging for the brand layer.
The short version
- Decide the carrier band first, then choose the format.
- Letterbox depth is the most valuable threshold for flat goods.
- Restraint beats cushioning in a parcel network.
- Specify the tape pattern and base construction, not just the tape.
- Decide re-closability from your actual return rate.
Frequently asked questions
What size should a parcel be?
Whatever sits comfortably inside the carrier band you want it in. Start from the band, not from the product, and check the external dimensions against published thresholds.
Do all carriers use the same size bands?
No. If you use several, specify to the tightest set so one format works everywhere rather than being economical with one carrier and surcharged by another.
Is bubble wrap enough for parcel delivery?
For surface protection sometimes; for stopping movement rarely. Most parcel damage is movement, which needs restraint.
What is the cheapest improvement we can make?
Measuring your highest-volume packs against carrier thresholds. It takes an hour and the saving recurs on every order in that format.
Can WSUK despatch the parcels as well?
Yes - parcel services and parcel fulfilment, with the packaging specified against the bands you actually ship against.