A 3PL invoice audit checks every charge against three things: is it allowed by your contract, is it backed by a recorded warehouse or shipping event, and is the rate and quantity correct? Start with the lines that change most from month to month, such as ad hoc labour, storage and surcharges, and log anything you cannot match.
An invoice can match the rate card and still be wrong: a charge billed twice, storage counted on the wrong date, or ad hoc labour with no record of the work. A simple monthly 3PL invoice audit catches these before they add up. This guide shows what to check, the records you need and how to raise a dispute.
Why should I do a 3PL invoice audit?
A third-party logistics (3PL) invoice combines many small charges from different systems: storage from the warehouse system, pick and pack from order records, shipping from carrier data and extras logged by staff. Errors are rarely deliberate, but they are common, and small recurring ones are easy to miss when you only look at the total.
Signs an invoice needs a closer look:
- New or unfamiliar line items.
- Ad hoc or “labour” charges without a description of the work.
- Totals rising faster than your order volume.
- Storage charges that do not fall when stock levels do.
- Surcharges that were not in the original quote.
How do I check each charge in a 3PL invoice audit?
Match every line to a contract term (which sets the rate) and an activity record (which proves the quantity):
| Charge | Contract term to check | Record to match | Question to ask |
|---|---|---|---|
| Storage | Billing unit (pallet, shelf, cubic metre), count date, minimums | Stock on hand report | Do billed units match stock on the count date? |
| Receiving | Per pallet, carton, container or hour | Receipts and ASNs | Does the quantity match what arrived? |
| Pick and pack | Per order plus per extra item | Orders shipped | Does the order and unit count match your store? |
| Shipping | Carrier rates, zones, fuel levy | Consignment data with weights | Are weights, zones and surcharges correct? |
| Ad hoc labour and extras | Hourly rate and what needs your approval | Work orders or approvals | Was the work requested and recorded? |
One of the real searches that brings people to Warenous is “I often find extra billing in ad hoc labour; what 3PLs have better transparency?” Ad hoc labour is the hardest charge to check because there is often no record behind it. The fix is in the contract: require written approval for any ad hoc work above an agreed amount, and a description of the task on the invoice.
How do I run a 3PL invoice audit step by step?
- Gather the documents. The invoice, your contract and rate card (with any amendments), and exports of stock on hand, receipts, orders shipped and consignments for the same period.
- Set up a simple spreadsheet. One row per invoice line, with columns for rate, quantity billed, quantity recorded, expected amount, difference and notes.
- Start where the money is. Shipping and storage are usually the largest lines; ad hoc labour and surcharges are the most likely to be wrong.
- Check for duplicates. Sort by order or consignment number to find anything billed twice.
- Check volumetric weights. Spot-check a sample of parcels: is the billed weight realistic for the box used? See how volumetric weight works.
- Log exceptions. Record each query as “to verify”, not as an error, until the 3PL has responded.
- Track trends. Compare cost per order month to month. A rising cost per order with stable volumes needs explaining.
What should I do if a 3PL invoice audit finds an error?
- Raise it in writing. List the invoice and line, the contract clause, your calculation and the supporting record.
- Keep it neutral. Ask for an explanation or correction rather than assuming fault; many queries turn out to be a rule that was never written down.
- Record the outcome. Note whether the charge was explained, credited or agreed, and save any clarified billing rule with your contract.
- Fix the cause. If the same issue repeats, agree a process change: clearer definitions, approval limits or better data from the warehouse system.
If errors keep recurring after that, it may be a sign of a wider fit problem. Our guide to hidden 3PL costs explains what to look for when comparing other options.
Frequently asked questions
How often should I do a 3PL invoice audit?
Check every invoice before you approve it, and do a deeper review every quarter or after any contract change, new service or big change in volume.
Do I need software for a 3PL invoice audit?
No. A spreadsheet with one row per invoice line and exports from your 3PL’s system is enough for most brands. Software helps once you have high volumes or several warehouses.
What records should my 3PL provide?
At minimum: stock on hand, receipts, orders shipped and consignment data with weights and zones. Ask for this access in the contract so audits are possible.
What are the most common 3PL invoice errors?
Duplicate charges, storage counted on the wrong date, incorrect volumetric weights, surcharges not in the contract and ad hoc labour without a record of the work.
What if my 3PL cannot explain a recurring charge?
Ask for the billing definition and the transaction records behind it. If it still cannot be explained, keep it open, escalate to your account manager and consider withholding that line until it is resolved, if your contract allows.
Tired of invoices you cannot check?
Warenous matches you with pre-screened 3PLs that bill clearly, and compares their quotes on your real orders, for free.
Book a free call with a 3PL expert
