How postage is worked out
Postage is priced on what the parcel actually is — how big it is and what it weighs — not on what kind of thing is inside it.
- The customer's country picks a zone.
- Everything in the basket is measured, and we work out which of your parcels it fits in, and how many you would need.
- Each postal method prices that parcel by weight. The cheapest one that will actually carry the order wins.
Your parcels
A parcel is the packaging you really post in. Give it the inside measurements, not the outside, and the heaviest it is allowed to be.
| Field | What it means |
|---|---|
| Width, height, depth | The usable space inside, in millimetres. |
| Max (g) | The heaviest the whole parcel may be, packaging included. For Royal Mail formats this is their limit. |
| Packing (g) | What the empty box or envelope weighs. It counts against the limit, so a heavy box leaves less room for stock. |
| Fill % | How much of the space is really usable once things are padded. 75% is a safe start. |
Start from Royal Mail sizes fills in their four formats. Replace them with your own envelopes and boxes if you post in something else — the sizes are what matter, not the names.
Pricing a method
Each postal method prices each parcel by weight, in bands, the way a carrier's own price list does. Fill in a pair — a weight and a price — and that band applies up to that weight. The last band you fill in is the heaviest that method will carry in that parcel.
Blanks are normal. Services use different numbers of weight steps: Royal Mail prices a small parcel at one weight and a large letter at four, and Tracked does not carry letters at all. Leave a parcel unpriced for a method and that method simply will not offer it.
A worked example
With a large letter at £2.05 up to 250g and £3.20 up to 750g, and a small parcel at £4.75:
| Basket | Postage | Why |
|---|---|---|
| 20 cards | £2.05 | 35g of cards, flat, goes as a large letter |
| 400 cards | £3.20 | 700g — same envelope, heavier band |
| 1 booster box | £4.75 | Too deep for a large letter, so it is a small parcel |
| 1 booster box + 20 cards | £4.75 | The box decides the parcel; the cards ride along |
| 6 booster boxes | medium parcel price | Too heavy for a small parcel, so it moves up again |
The number tells you which parcel it packed into, which makes it easy to check your prices are doing what you meant.
Where the measurements come from
For anything from the shared catalogue — cards, sealed product, accessories — we hold the sizes centrally. A booster box is the same size in every shop, so those figures are not yours to edit, and you do not have to measure anything.
For products you add, you give the size and weight on the product itself. They are required, because we cannot work out postage without them. If you leave a type's default size and weight set on this page, anything of that type falls back to it.
Collection
The first panel on the page, and its own save. Tick Let customers collect in store, free and press Save collection, and collection is offered at the checkout alongside the post — at no charge, and to anyone, wherever they are. Untick it and every order has to be posted. A product marked Collection in store only is collected regardless of this switch.
What the customer sees
The three cheapest options, collection included. Seven near-identical services is a wall of choices, so we show the few that matter. If that is not the mix you want, remove the services you do not offer.
They have to choose one before they can pay. If they picked something and then changed the basket so it no longer carries, the choice is dropped and they are asked again — rather than quietly falling back to collection and posting it for nothing.
When nothing can carry it
If an order fits none of your parcels, no postage is offered and the customer is told so, rather than being charged nothing and having it posted anyway. If that happens for something you do sell, add a parcel big enough for it.
What is not posted
A product marked collection in store only never gets postage and forces the whole basket to collection. Gift cards go out by email, so they never add to a postage charge.