Should we withhold payment on disputed lines?

Sometimes, and only on the disputed amount. Check your payment terms and internal policy first, tell the supplier explicitly what is being withheld and why, and release it as soon as the credit lands.

How long should we give a supplier to respond?

Two to three weeks for a documented batch is reasonable, with a named follow-up date. Anything open past two cycles should escalate rather than be re-sent.

What if the overbilling goes back years?

Claim it, but expect the older portion to be negotiated. Recent, in-window lines are usually credited on evidence alone; older lines become a commercial conversation, often settled as a lump credit or a forward pricing concession.

Rarely. The overwhelming majority of price-compliance claims settle at the account-manager level once the evidence is clear. Legal escalation is for systemic, high-value cases where the agreement itself is in dispute.

Recovery

When a supplier won't credit an overcharge

Finding off-contract billing is the easy half. This is the escalation path that gets it credited — what to document, what to send, and how to answer the four objections you will always hear.

Start free Estimate your leakage

Before you escalate, make sure the finding is clean: the audit checklist and how discrepancies arise.

Start from evidence, not indignation

Almost every dispute that stalls stalls for the same reason: the claim asserts an overcharge without showing the contracted price, its effective dates, and the arithmetic. Before you send anything, each line should carry the invoice number and date, the part number as billed, the quantity and unit, the price billed, the contracted price in effect that day, the price list version it came from, and the extended difference.

Send one batch, not a stream

Group by supplier and by period — a month or a quarter — rather than one email per line.
Lead with a one-paragraph summary: number of lines, total claimed, period covered.
Attach the line detail as a spreadsheet the supplier's team can filter, not a PDF.
Name a single contact on your side and ask for a single owner on theirs.
Set an explicit response date. Claims without a date drift indefinitely.

The four objections you will hear

"That price expired." Correct — which is why the comparison uses the price in effect on the invoice date. Show the version history.
"That was a quoted price for a different job." Fine. Then it should not have applied here, or it should have. Either way the quote's scope resolves it.
"The units are different." Show the normalization: contract per square, invoice per bundle, the conversion, and the result.
"We already credited that." Ask for the credit memo number and reconcile it against the claim. If it paired with a rebill at the wrong price, the claim stands.

Escalation, in order

Inside sales rep or branch manager — resolves most routine, in-window claims.
Regional or national account manager — for anything systemic across branches.
Supplier's contract administration or pricing team — for expired-list and version-control failures, which are their process problem, not the rep's.
Your own procurement lead, with a scorecard — error rate, dollars, days-to-credit — at the next business review.
Withholding disputed amounts from payment: effective, but check the payment terms and your own policy first, and never withhold undisputed amounts.

What a workable claim letter contains

Reference to the governing agreement and the period audited.
The count of lines and the total claimed, stated once and clearly.
The per-line schedule with contracted price, billed price and difference.
The remedy requested — a credit memo to the account, not a check, in most cases.
A response date and your single point of contact.

Keep the relationship intact

The goal is a supplier who bills correctly next month, not a win. Frame findings as a process defect on their side that you are helping surface — usually it genuinely is — and share the scorecard rather than the grievance. Suppliers who see the measurement tend to fix the price file, which is worth more than the credit.

Common questions

Should we withhold payment on disputed lines?: Sometimes, and only on the disputed amount. Check your payment terms and internal policy first, tell the supplier explicitly what is being withheld and why, and release it as soon as the credit lands.
How long should we give a supplier to respond?: Two to three weeks for a documented batch is reasonable, with a named follow-up date. Anything open past two cycles should escalate rather than be re-sent.
What if the overbilling goes back years?: Claim it, but expect the older portion to be negotiated. Recent, in-window lines are usually credited on evidence alone; older lines become a commercial conversation, often settled as a lump credit or a forward pricing concession.
Do we need a lawyer?: Rarely. The overwhelming majority of price-compliance claims settle at the account-manager level once the evidence is clear. Legal escalation is for systemic, high-value cases where the agreement itself is in dispute.

See your own numbers

Audit your first 500 invoice lines free. No card, no sales call.

Audit my invoices free See pricing Read the field notes