How to read a 3PL invoice, and the three checks to run every month.

A 3PL invoice bills you for what the warehouse did in a period, and every line on it should move with something you can count yourself: orders shipped, cubic feet stored, parcels returned, hours you asked for, parcels carried. To read one, match each line to what drives it, check the quantity against your own exports and the rate against your agreement, then divide the total by your orders. If a line doesn't move with anything you can count, that's the one to ask about first.

Here's how we'd read one, with a table of the usual lines, the three checks we'd run every month, and what to do when a charge has no explanation behind it.

What you'll find on a 3PL invoice

Most 3PL invoices have a header and a body. The header gives the billing period and the invoice date, plus your account number. Check the period first, because a handling line for the first to the last day of the month should match your orders for those same days, and a period that starts on the third will throw every comparison off.

The body is a list of charges, each with a description, a quantity, a unit and a rate. People tend to skip the unit, and it's the part that matters. "Handling: 1,000 orders at $3.00 per order" tells you what was counted. "Fulfillment services, $3,000" with no quantity tells you nothing you can check, so ask for the quantity and the unit on every line before you look at anything else.

You may get more than one bill. Many 3PLs invoice handling and storage once a month and bill postage on its own schedule, since carriers bill the warehouse as parcels move. That's normal, and what matters is that you can see which parcels and which days each bill covers, so nothing lands on two invoices and nothing falls between them.

What each line on the invoice should move with

Every charge has a driver, the thing that makes it go up or down. Once you know the driver, you know which of your own reports to hold it against. Here are the lines you'll usually see.

Two lines catch brands out more than the rest. The per-item pick line grows with basket size, so a promotion that pushes shoppers from two units to four can raise your bill on the same order count. And storage depends on when the cube is measured, which our guide to storage fees works through with a falling month of inventory. If you're still comparing quotes, the hidden fees checklist shows where each of these lines tends to hide before you sign.

The exports you need before you open the invoice

You can't check a quantity without your own count of the same thing, and you don't want to rely on the 3PL's report to check the 3PL's invoice. Pull these for the billing period before you start. Most of them come from systems you already run.

• Fulfilled orders from your store, with order date, fulfillment date and units per order. Pull it from each channel's order report, and if you sell on more than one, add them up.
• An inventory snapshot by SKU on the storage measurement date, from the warehouse dashboard or your own inventory system, with the cube per unit next to each SKU.
• Your inbound log: every shipment you sent, with the packing list, carton count and the date the warehouse marked it received.
• Returns: the count of return labels used, from your returns portal or carrier account, for parcels delivered back to the warehouse in the period.
• Every request you sent the warehouse for extra jobs, with the date and the hours or price you agreed.
• Your rate schedule, the page of your quote or agreement that lists each rate and its unit. Keep the version that was in force for the period you're checking.

Put them in one sheet with a row per invoice line. It takes an afternoon the first month and about an hour after that, because the columns don't change.

The three checks to run every month

You don't need to audit every parcel. These three checks catch nearly everything that matters, and they run in this order because each one builds on the last.

1. 01Check the quantities. For each line, put the invoice quantity next to your own count from the exports. Handling against fulfilled orders, returns against parcels received, storage against your snapshot cube. Small gaps have ordinary causes, like an order fulfilled on the last day that the warehouse counted the next morning. A gap that's large, or that runs the same direction every month, is a question to send.
2. 02Check the rates. Read each rate against the schedule for that period. Rates drift for honest reasons: a new line got added for a one-time job and stayed, or a holiday rate didn't come off in January. Ask whether any handling or storage rate changes by season, and if it does, check the dates it applied.
3. 03Check the ratios. Divide each line by orders shipped and keep the results month by month: handling per order, storage per order, packaging per order, returns per order, postage per order. Say storage per order jumps one month while your inventory held steady. You've found something the first two checks missed, maybe a measurement on the wrong day or a new location charge.

The ratios are also how you'll see a trend coming. Packaging per order creeping up usually means orders are going out in bigger cartons than the SKU needs. Receiving per inbound creeping up usually means your shipments are arriving harder to count, which the guide to sending inventory can fix on your side. The full formula for cost per order, with a month worked through, is in fulfillment cost per order.

How to read the postage lines

Postage can be a big share of the bill, and it's the hardest line to check from a total. Ask for it per shipment: tracking number, service, billed weight, dimensions, zone and charge. With that file, you can sort by charge and look at the top of the list, where mistakes cost the most.

Billed weight is worth a look on its own, because it isn't always the weight on the scale. USPS prices Priority Mail parcels over one cubic foot, 1,728 cubic inches, on actual or dimensional weight, whichever is greater, and finds the dimensional weight by multiplying length, width and height in inches and dividing by 139 (checked October 2026). The USPS commercial price list applies the same one-cubic-foot rule to Ground Advantage parcels (checked October 2026). So a light product in an oversized carton can be billed as if it were heavier. If billed weight runs well above what your products weigh, ask which cartons those parcels went out in.

Now and then you'll see a charge on a tracking number from an earlier period. Don't let it blend into this month's total. Ask the warehouse what the charge is for, and ask for it to be labeled as an adjustment and tied to the original parcel, so you can see how often it happens and why.

What a line nobody can explain means

Sooner or later you'll find a charge you can't match to anything. Don't assume it's wrong, and don't pay it without asking. Send one email that names the line, the quantity and the period, and ask for the backup: the order numbers behind a handling count, the receiving record behind an hourly charge, the request behind a special project.

A warehouse that runs on a proper system can answer that in a day, because the invoice was built from scans and timestamps. If the answer is a correction, ask for it as a credit on the next invoice with the line it reverses. If the answer is a fee you didn't know about, find it in your rate schedule. Was it there all along, or did it appear without notice?

What the answer tells you matters more than the amount. One explained charge is ordinary. A charge nobody can trace to an order, a parcel or an hour means the invoice isn't built from the warehouse's own records, and the same gap will turn up somewhere else next month. If it keeps happening after you've asked, read the signs it's time to switch 3PLs, since billing you can't check is one of them.

How a month's billing reads at YNK

We bill the way we'd want to be billed as brand owners: every line itemized, each with its own quantity and unit. Handling and storage are invoiced monthly, and postage is billed semi-monthly per shipment, at extremely competitive carrier rates. Our rate card has the estimated rates, and your quote confirms the exact ones once we've seen your volume and what you ship.

• Handling: an estimated $3.00 per order, pick, pack and ship included. One handling fee per order is the baseline, however many units are in it, and if your order profile is priced differently, your quote says so.
• Storage: an estimated $0.65 per cubic foot per month, billed on the space you use, so it falls as you sell through.
• Returns: an estimated $3.00 per parcel, received, graded and restocked or set aside by your rules.
• Receiving: billed by the hour, with the rate confirmed in your quote. A labeled shipment with a packing list takes fewer hours than a mixed pallet without one.
• Packaging and supplies: billed as they're used.
• Special projects: $35 an hour, only when you ask for one.
• Not on the invoice: a setup fee, a charge for the Shopify, Amazon or TikTok Shop connections, the WMS or the dashboard, or any seasonal or peak surcharge on handling or storage.

Say you shipped 1,000 orders in a month, held 400 cubic feet and took back 30 returns. Handling is 1,000 times $3.00, or $3,000. Storage is 400 times $0.65, or $260. Returns are 30 times $3.00, or $90. That comes to $3,350 for the month, about $3.35 an order, before receiving hours, packaging and postage, and the same rates apply in December. You can run your own month in the cost calculator.

To check those quantities, you don't have to ask us for a report. The live dashboard we run our own brands on shows every order's status and your inventory by SKU, and cycle counts keep the dashboard count equal to the shelf count. If a number on the invoice doesn't match what you see there, email us and someone from the team replies within one business day.

Questions founders ask about 3PL invoices