If you’ve ever processed invoices where suppliers bill tariffs separately, you know how messy purchase order (PO) matching can get. We’re hearing more prospects and clients recently surface this pain point during their implementation: suppliers add tariffs as separate invoice lines, but procurement wants those costs rolled into item unit costs for better landed cost tracking. The result? A constant tug-of-war between how vendors bill and how finance wants to record.
It’s a nuanced challenge, and one that many manufacturing and distribution companies face. Let’s unpack why tariffs complicate matching and how AP teams can manage them cleanly in Centime without breaking audit trails or workflows.
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Why Separate Tariff Lines Throw Matching Off
On paper, separate tariff lines sound harmless. In practice, they break the 1:1 relationship between the PO and invoice lines that automated matching relies on.
Centime’s PO matching engine links invoice lines to their corresponding PO lines based on rate, quantity, description, and item code.
When an invoice adds a tariff as a new line, there’s no matching PO line — so the system flags it as unlinked or new.
This creates three ripple effects:
- Unit-of-measure (UOM) mismatches:
When tariffs are blended back into unit costs, quantity-based POs (like kg or liters) can produce fractional differences. Matching logic then has to reconcile an invoice cost-per-kg that’s higher than what’s on the PO. - Added or deleted lines:
If AP deletes the tariff line and redistributes the amount across items, the invoice no longer mirrors the supplier document — creating potential audit friction. - Posting and auditability:
Posting a modified invoice means the bill total matches, but the line structure doesn’t. Without clear documentation, this can obscure cost allocation decisions later during audits.
The Real-World Workaround (and Its Pitfalls)
Many finance teams have a current workaround that’s pragmatic but imperfect:
- Delete the tariff line from the invoice.
- Manually distribute that cost into item unit costs.
- Post the invoice.
- Then, adjust the PO to match the new item cost basis.
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It works — but it’s easy for mismatches or audit confusion to creep in if the process isn’t tracked tightly. Once that tariff cost is blended into unit prices, you lose line-level traceability of the original tariff.
Two Ways to Handle Tariffs in PO Matching
There’s no one-size-fits-all approach here. The right strategy depends on whether tariffs are consistent, variable, or one-off.
1. Keep Tariffs as Separate Line Items
Use this if tariffs are billed consistently or as a standard percentage.
- Create dedicated tariff lines on POs so invoices align automatically.
- Let Centime’s line linking logic handle the match cleanly, with clear visibility into each charge.
- Benefit: no manual edits, no risk to audit history.
2. Roll Tariffs into Item Costs
Best when tariffs are variable and change with each shipment.
- Delete or unlink the separate tariff line on the invoice (Centime allows unlinking without deleting the invoice line entirely).
- Adjust the per-unit rate on the PO lines and rerun the matching logic to align totals.
- Use Centime’s audit trail — every action (unlinking, relinking, posting) is recorded in the matching history.
- Benefit: cleaner landed cost tracking in the GL, without losing visibility into what changed and why.
Keeping Matching and Audit Trails Clean in Centime
If you’re redistributing tariff costs, a few best practices help maintain integrity:
- Use the “re-run linking logic” option after edits so status recalculations reflect the new cost structure.
- Add notes when unlinking or accepting tariff-related lines, so future reviewers understand the adjustment.
- Require AP and procurement coordination: Once the invoice is posted, procurement should update the PO in the GL to mirror the adjusted rates. This keeps everything in sync before the next shipment hits.
- Leverage mismatch thresholds: Centime lets you define rate and amount thresholds — so small tariff adjustments fall within acceptable tolerance bands rather than triggering unnecessary reviews.
Closing Thoughts
Tariffs are part of doing business — but the headaches they cause in PO matching don’t have to be. The real challenge isn’t avoiding complexity; it’s keeping control over it. With the right automation, AP teams can stay accurate, auditable, and fast without endless manual edits.
Centime’s PO matching engine already accounts for the messy realities of global supply chains — from tariff adjustments to unit-of-measure mismatches — helping teams post confidently and stay compliant.
If your AP team is still wrestling with invoice workarounds, book a demo to see how Centime can simplify matching and keep your audit trail spotless.