What actually happens between you entering a parcel's dimensions and a list of carrier prices appearing.
Carrier pricing is not uniform. Each operator has built a denser network in some countries than others, with different hubs, different final-mile partners and different volumes on each lane. A carrier moving a lot of freight between Portugal and Spain has better economics on that lane than one that barely runs it, and that difference lands directly in the price you are quoted. Weight compounds it: some carriers price light parcels aggressively and become uncompetitive above twenty kilograms, while others are structured the opposite way.
The consequence is that no carrier is permanently cheapest, and picking a favourite means overpaying on every route where that favourite happens to be weak. The only way to know is to price the actual parcel on the actual route with several carriers — which, done manually, means filling in the same form on four or five different websites.
A comparison platform collapses that into one form. You enter the parcel once, it queries the carriers it has agreements with, and it returns their prices side by side. That is the whole concept. Everything else is detail about how well it is executed.
Dimensions, weight, origin and destination postcodes are validated and converted into the format each carrier's system expects. This is also where a bad postcode gets caught, before it becomes a failed collection.
Each carrier applies its own volumetric formula — commonly length × width × height in centimetres divided by 5000, though some express services use 4000. The platform applies the correct divisor for each, so the prices you compare are genuinely like for like.
The platform calls each carrier's pricing system with your normalised parcel. Carriers that cannot serve the route, or cannot accept the size or weight, simply return nothing.
Remote and island area surcharges, fuel adjustments, residential delivery rules and oversize handling get folded in, which is why a real quote can differ from a rough estimate you calculated yourself.
You see price alongside estimated transit time and whether the service is drop-off or collection. Reading all three together is the difference between a good booking and a cheap one.
The platform books with the carrier you picked, and the label and tracking reference are issued. From that point the parcel is in that carrier's network.
Comparison platforms buy carrier capacity at negotiated volume rates and resell it. Because they aggregate the shipments of many customers, they reach volume tiers that an individual sender or a small business could not negotiate alone, and the margin sits in the gap between that negotiated rate and the price shown to you.
This is worth understanding plainly rather than treating as a hidden catch. It means the relevant comparison is not 'platform price versus the carrier's cost' but 'platform price versus what you personally could book that carrier for'. For a sender without negotiated accounts, the compared rate frequently beats the carrier's own published direct price, because you are buying inside someone else's volume agreement.
It also explains where the model stops helping. If you ship enough volume on consistent lanes to negotiate your own carrier rates, those rates may beat a platform quote on exactly those lanes. The sensible response is not loyalty in either direction: compare your negotiated rate against the platform quote and use whichever is lower.
The cheapest row is not automatically the right booking.
| Column | What to check |
|---|---|
| Price | The headline figure — but never read it alone |
| Transit time | Whether it actually meets your deadline. A cheaper service that arrives too late is not cheaper |
| Drop-off or collection | Comparing a drop-off rate against a collection rate makes one look artificially cheap |
| Delivery type | Door-to-door, or to a pickup point the recipient must travel to |
| Carrier | Relevant if the recipient has a preference, or if a carrier has known issues on that lane |
| Duties and taxes | On non-EU routes, whether duty is prepaid or left for the recipient on arrival |
Entering estimated dimensions rather than measuring the sealed box — the carrier re-measures and re-charges, wiping out the saving you thought you found.
Sorting by price and booking the top row without reading the transit time next to it.
Comparing a drop-off rate from one carrier against a collection rate from another.
Assuming the carrier that was cheapest last time will be cheapest this time — weight and destination both change the ranking.
Ignoring that duty and VAT on non-EU routes sit outside the quoted price entirely.
Treating a shorter results list as a worse platform, when it may simply reflect which carriers genuinely serve your route.
When going straight to a carrier makes more sense, and when it does not.
Read more →What each carrier is structurally good at, and the four questions that decide your choice.
Read more →The five components that build every quote, and which of them you control.
Read more →The formula that decides chargeable weight, with worked examples.
Read more →They buy carrier capacity at negotiated volume rates, aggregating the shipments of many customers to reach tiers an individual sender could not reach alone. You are effectively buying inside someone else's volume agreement, which is why a compared rate often beats a carrier's published direct price.
They are real for the parcel you described. The charge changes only if the parcel does not match what you entered — carriers re-measure and re-weigh at their sorting hubs and adjust where there is a discrepancy. Accurate dimensions at the booking stage are what make the quote final.
Because they cannot serve that shipment. A carrier may not cover the destination postcode, may not accept the size or weight, or may have no service matching the route. A shorter list usually reflects the route's reality rather than a limitation of the platform.
Physical liability rests with the carrier, governed by the CMR Convention for road carriage and the Montreal Convention for air. The platform's role is to raise the claim with the carrier on your behalf and relay communications accurately. Your recovery is capped by the value you declared at booking.
Not by itself. What matters is how many of the listed carriers can actually collect from your address and serve your route competitively. A platform listing twenty carriers of which three serve your lane is not better than one listing five that all do.
Enter one parcel and watch DHL, UPS, FedEx, DPD and GLS come back priced side by side, with transit times.
Compare Rates Now →