How to handle a client invoice dispute

A disputed invoice needs diagnosis before collection pressure. The client may question identity, scope, quantity, quality, price, tax, approval, or payment already made. Isolate the disputed element, preserve the undisputed balance, and answer with documents rather than emotion.

This is a commercial documentation workflow, not legal advice. Limitation periods, lien or holdback rights, consumer rules, and collection remedies vary by province and contract. Seek advice before a deadline or material escalation.

Classify the dispute

First response template

Subject: Review of invoice INV-1048 - disputed line

Hello Morgan, Thank you for flagging the concern with invoice INV-1048. I understand that you dispute the four additional labour hours on line 3. I am reviewing the approved change request and dated work log. The other invoice lines total CAD 1,920.00 and are not part of the issue as I understand it. I will send the supporting documents or a proposed correction by September 3. Please reply if another line is also disputed.

This confirms the issue without conceding facts prematurely. It also asks whether the undisputed balance can proceed under the original terms.

Build one evidence file

• Signed contract or accepted estimate and original scope.
• Change orders, approvals, purchase orders, and rate confirmation.
• Dated work logs, photos, delivery records, and client sign-off.
• Original invoice, tax calculation, and proof of delivery.
• Payments, credits, and earlier correspondence.
• A neutral chronology of calls, promises, and proposed resolutions.

Resolve without corrupting the invoice trail

If the original invoice is correct, explain the calculation and attach the smallest evidence set that resolves the question. If an administrative field is wrong but the amount is unchanged, issue a clearly marked revision while retaining the original. If price or tax changes, use a credit/debit note or other appropriate corrected document.

Do not silently edit a PDF already in the client's system. Use Credit Notes and Invoice Corrections in Canada for the traceable adjustment. If the client accepts a payment plan, preserve the original invoice total and record each instalment against it.

Escalation checkpoints

• Confirm the contractual notice and dispute procedure.
• Separate undisputed and disputed amounts in writing.
• Set a reasonable date for documents and response.
• Consider a project-level meeting before third-party collection.
• Check provincial deadlines and construction-specific rights before they expire.
• Stop new work when the exposure is material and the contract permits it.
• If collection fails, organize the file with Bad Debts, Unpaid Invoices, and GST/HST.

Should I cancel an invoice when a client disputes it?

R: No. First identify the disputed facts. Cancel or credit only when a supported resolution changes the amount or supply.

Can I ask for the undisputed amount?

R: Yes, clearly identify it and refer to the contract. Whether it is legally enforceable on the original date depends on the agreement and local law.

Should phone calls be documented?

R: Yes. Send a short factual recap with the date, issue, commitments, and next deadline.

When is legal advice appropriate?

R: Before a limitation, lien, holdback, or contractual notice deadline, and whenever the amount or business risk makes informal resolution insufficient.