Get the invoice in usable form.
Most AU 3PLs send invoices as PDFs. Ask for CSV or Excel — every reputable 3PL can provide this. Without structured data, line-level audit is too time-expensive to sustain monthly.
If your 3PL refuses CSV, that's its own audit signal. Ask why.
The five-line audit.
1. Pick & pack quantity. Reconcile against your order count and items-per-order from your OMS. Most common error: 'storage handling' or 'special pick' lines that shouldn't have triggered.
2. Storage charges. Reconcile against your actual pallet count from the WMS report. Common error: pallets billed on peak count rather than month-end count, or month-end count rather than average.
3. Receiving / inbound. Reconcile against actual inbound POs received. Common error: receiving fees billed on quoted ASN quantities not actual received quantities.
4. Hidden fees and surcharges. Anything line-itemed that isn't in the rate card. Fuel surcharge on shipping (especially if you're on cost-plus), special-project hours, kitting fees, sample fees, label re-print fees. Demand SOW or written approval for anything ad-hoc.
5. Shipping pass-through (if applicable). Compare to the actual carrier invoice if your contract gives you visibility. Margin-loading on cost-plus shipping is the #1 hidden cost we see.
Common errors we see.
Volume tier creep: rates that should drop at 2,000 orders/mo or 5,000 orders/mo not actually dropping when you cross the threshold. Easily $300–$1,200/mo in lost savings.
Long-term storage misclassification: inventory under 90 days getting billed at long-term rates because of a date stamp issue. $200–$800/mo at risk.
Phantom pick lines: 'replenishment picks', 'inventory move picks', or 'cycle count picks' that should be 3PL operational cost, not billable to you. $100–$500/mo.
Re-pick / re-pack fees: 3PL errors being billed back to you. Should never happen — flag and recover.
Run it monthly. It compounds.
Brands that audit invoices monthly recover an average of $400–$1,500/month in our audit set. That's $5,000–$18,000/year of recovered margin from 30 minutes of operational discipline.
More importantly, the act of auditing keeps the 3PL honest. Contracts with regular invoice audits show meaningfully lower hidden-fee creep than contracts that never get audited.
When to escalate.
First error: flag, ask for credit on next invoice. Most 3PLs will credit without argument.
Second error in same category: written notification, request process review, ask what's changing.
Pattern of errors: schedule a quarterly review with your 3PL account manager and your finance lead. Document the pattern.
Want a free invoice audit?
Send us your last 3 months of 3PL invoices. We'll line-audit them and send back the recoverable errors — independent, free, paid by 3PLs only when we make an introduction.
Get matched →Frequently asked
- How long does a monthly invoice audit take?
- 20–40 minutes once you have the data flow set up. The first audit is harder (1–2 hours) because you're learning the line items and how to reconcile.
- Should I audit every invoice or sample?
- Every invoice. Sampling misses systematic errors that show up across months. The 30 minutes is worth it.
- What if my 3PL won't give me CSV invoice data?
- Push hard — every reputable AU 3PL can provide structured invoice data. Refusal usually signals a 3PL that doesn't want their pricing transparent. That's a flag.
Cite this page as: 3PL Compare. (2026). How to audit a 3PL invoice — the line-by-line process (2026). Retrieved from https://3plcompare.com.au/how-to-audit-3pl-invoice