You don't need a full audit to know whether it's worth doing one. These seven checks each take about 10 minutes and use records you already have access to.
None of these seven signs prove overbilling on their own — invoices are complex, and most mismatches turn out to have a benign explanation. But each one is a specific, checkable thing, not a vague feeling that "the invoices seem high." If two or three of these turn up something, that's usually the point where a full line-by-line audit against your rate card starts to pay for itself.
Rate cards don't change themselves. If your per-order pick fee is higher than it was a year ago and you can't point to a signed amendment explaining why, that's the single most common finding in a 3PL audit.
10-minute check: Pull one invoice from this month and one from 12 months ago. Compare the pick-fee line. If it moved and you don't have a signed amendment dated in between, you have a starting point.
Storage is billed by space — bins, shelves, or pallets — and it's one of the easiest categories to bill incorrectly, because it depends on someone accurately tracking your physical footprint inside someone else's warehouse.
10-minute check: Ask your 3PL's portal (most have one) for a current inventory snapshot showing pallet/bin count. Compare it to this month's storage line. A mismatch of even 10–15% is worth a closer look.
Hourly receiving charges are legitimate when the work happened — but they're also the easiest fee to pad, because there's rarely an independent record on your side of how long an inbound shipment actually took to process.
10-minute check: Ask for the receiving log or timestamp record behind any hourly receiving charge over 2 hours. A 3PL with nothing to hide will have this on hand.
A minimum fee clause should mean: you pay the minimum or your actual usage, whichever is greater — never both. Occasionally a billing system applies it additively by mistake.
10-minute check: Add up every itemized charge on one invoice. If that total already exceeds your contracted minimum, and the minimum still shows up as a separate line, flag it.
This one is rarer, but it happens — usually from a data-sync issue between your 3PL's returns system and your storefront, not intentional overbilling.
10-minute check: Pull your return count from Shopify (or your OMS) for the billing period and compare it to the return line count on the invoice. They should match exactly.
3PLs periodically migrate billing systems, and fee categories sometimes get renamed or restructured in the process. That's not inherently a problem — but it's a moment where a rate that should have carried over correctly sometimes doesn't.
10-minute check: If you got a notice about a billing system change in the last year, pull an invoice from just before and just after. Re-map each renamed category back to your original rate card and confirm the underlying rate didn't shift along with the label.
This isn't a billing red flag on its own — it's the reason the other six are hard to catch. Most invoice errors aren't caught because nobody at the brand has the rate card and 20 invoices open side by side; they're caught because nobody has time to.
10-minute check: Set a recurring 30-minute quarterly calendar block to spot-check one invoice against your rate card, category by category, using the checklist in our full audit guide.
None of these turned anything up, but you're still not sure? That's normal — a lot of overbilling is small enough per-line that it only becomes visible once every category is checked systematically against the actual signed rate card, which is exactly what a full audit does.
Send one invoice and your rate card. We'll check it against every category above and tell you what we find — free, no commitment.
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