Guide · Multi-carrier routing
Multi-carrier shipping from China means each parcel is assigned its carrier channel at dispatch time rather than the merchant committing to one carrier. WooliiPorter decides in three fixed layers: a compliance gate that fails closed, a transit-band match against the promise the merchant chose, then cost selection among the channels that survived both.
The alternative is doing it yourself: one contract, one rate card and one integration per carrier, renegotiated as lanes change. A network moves that work to the routing layer — the merchant integrates once, and the per-parcel decision is run, and recorded, by the system that also operates the warehouse.
Three layers could be combined into one weighted score, and that would be a mistake: a score lets a very cheap channel outbid a compliance problem. Keeping the layers ordered and absolute is what makes the decision explainable — every elimination has exactly one reason.
A parcel on a channel that cannot legally carry it does not arrive late — it gets returned, seized or destroyed. No price and no speed compensates for that, so the gate runs before either is considered.
The transit band is chosen by the merchant at booking and frozen on the parcel. Routing’s job is to honor a commitment that already exists, so only channels banded at or inside that range remain candidates.
Among channels that are compliant and keep the promise, cheaper is simply better. Cost decides the tie — it never overturns the layers above it.
Every check runs against measured and confirmed facts: the packed parcel’s weight and dimensions as the warehouse recorded them, and the cargo type as the operator confirmed it at receiving. A channel that fails any single check is eliminated regardless of price or speed.
| What is checked | What disqualifies a channel |
|---|---|
| Declared value | The parcel’s declared value exceeds the channel’s per-parcel ceiling, or falls below a destination’s per-item floor. |
| Weight | The measured packed weight — not the estimate — exceeds the channel’s cap. |
| Dimensions | Longest side, second-longest side, dimension sum or girth exceeds the channel’s limits, or the destination rejects the parcel’s shape outright. |
| Cargo type | The channel does not accept the parcel’s confirmed cargo type — battery, cosmetic, liquid, powder — as recorded by the warehouse operator at receiving, not as inferred from a store category. |
| Destination coverage | The channel does not serve the destination country, or the postcode resolves to a zone the channel has no rates for. |
At booking you choose a transit band — a destination-and-time-range product such as 8–12 working days — and that choice is frozen on the parcel. Routing keeps only the channels whose band honors it. Channels are assigned to bands by their upper bound, conservatively: a channel is banded by the slowest delivery it still stands behind, never by its best day. The full methodology, including why a single day-count promise is not one, is in the transit-bands guide.
The surviving channels are all compliant and all keep your promise, so the remaining difference that matters is cost, and the routing engine takes the cheaper channel. This is also where the network earns its keep over time: more connected channels on a lane means more survivors at layer 3, which means the cost selection has more to choose from — without you renegotiating anything.
The routing principle that does the most work is the least glamorous one: when an input is missing or ambiguous, the decision closes rather than guesses.
| Missing or ambiguous input | What happens instead of a guess |
|---|---|
| The declared value is missing | The parcel is treated as exceeding every declared-value ceiling — over-limit until declared, not compliant until caught. Declaring it restores the candidates. |
| The postcode does not resolve to a rate zone | The channel offers no rate for that parcel. The system does not guess an adjacent zone, because a guessed zone is a wrong price or a wrong promise discovered after dispatch. |
| The cargo type is unconfirmed | Routing waits for the warehouse operator’s confirmation at receiving. A battery routed as general cargo is a compliance failure in transit, which is the most expensive place to discover it. |
| No channel survives all three layers | The lane shows no offer for that band rather than a degraded one. An empty result is information; a silently substituted promise is a defect. |
The decision does not just produce a winner — it produces a record: which channels were candidates, which layer eliminated each one, and why the survivor won. That record stays attached to the parcel. When a shipment raises an exception, the conversation starts from the logged decision, not from a reconstruction — and when you ask why a lane offers what it offers, the answer is readable rather than folklore.
The network property worth restating as a plain mechanism: each fulfillment provider WooliiPorter connects adds its full channel set to every shipment you book, with zero changes on your side. Your integration surface — plugin, API or MCP — does not change when the network grows. The routing decision simply has more candidates to screen.
A fulfillment model where the carrier channel is chosen per parcel at dispatch time, from every channel available on the parcel’s lane, instead of the merchant contracting and integrating carriers one by one. The routing system screens channels for compliance, matches them to the delivery promise the merchant chose, and then picks on cost.
In three fixed layers: first a compliance gate — declared value, measured weight, dimensions, confirmed cargo type, destination coverage — which fails closed; then a transit-band match, keeping only channels whose banded range honors the promise frozen on your parcel; then cost selection among the survivors. Cost never overrides the first two layers.
The decision fails closed. A parcel without a declared value is treated as over every ceiling, and a postcode that does not resolve to a rate zone yields no rate rather than a guessed one. Missing data narrows the candidates; it never widens them.
No — that is the point of the network. You integrate once (store plugin, Merchant API or MCP), and each fulfillment provider WooliiPorter connects adds its full channel set to every shipment you book, with zero changes on your side. WooliiPorter is the only carrier identity you deal with; the channel selection stays inside the network.
The routing decision is recorded per parcel, including the elimination reason for each rejected candidate — failed the gate, missed the band, or lost on cost. When an exception is raised, your operator and ours read the same decision record instead of reconstructing it from memory.