When a supplier bills for extra work you dispute, first reconstruct what was agreed, who approved it and what was delivered. Keep the original scope separate from each alleged variation. An unsigned change order does not automatically settle the dispute either way: emails, conduct, authority and the contract’s own terms may also matter. Get advice before making admissions or ignoring threatened proceedings.
Raffles Corporate Services works with a panel of experienced Singapore law firms who offer cost-effective and efficient legal service and advice. This article is general information only and is not legal advice.
Build a variation-by-variation schedule
Do not review a large final invoice as one unexplained total. Give each disputed item a reference and identify the supplier’s description, claimed amount, claimed approval date and your response. Link the item to its supporting documents. Mark information that is genuinely missing rather than filling a gap with an assumption.
A useful schedule has separate columns for the original requirement, requested change, person involved, quoted price, work delivered and payment made. This often reveals whether the disagreement is about scope, price, quality or authorisation. Each issue calls for a different response.
Which documents should you preserve?
- The signed contract, quotation and original specification, including incorporated terms.
- Change requests, revised drawings, estimates and purchase orders.
- Complete email threads and exported messages, with dates and attachments.
- Progress reports, delivery records, test results and complaints.
- Invoices, payment records, credit notes and earlier settlement proposals.
Keep the originals alongside any working copies. A screenshot showing one message can leave out the request it answered or a later qualification. Preserve the surrounding conversation and identify the author. Do not edit a message history to make the company’s position appear stronger.
Who was allowed to approve the extra work?
Check both the contract and the company’s approval arrangements. A site contact or project manager may have permission to discuss technical matters without authority to commit the company to an additional price. Equally, internal limits do not automatically resolve what a supplier reasonably understood from the transaction. Give the full facts to the adviser assessing authority.
The Electronic Transactions Act addresses electronic records, signatures and contracts. Do not dismiss an approval trail simply because it is electronic, or assume every informal message forms a binding agreement. The wording, context, authority and applicable exceptions need assessment.
Separate the undisputed amount from the dispute
Ask your adviser whether and how an undisputed balance should be paid. Record the intended allocation and the company’s position clearly. Avoid labelling a transfer “full and final settlement” without advice on what that proposal means and whether it has been accepted.
Do not assume that raising an invoice dispute pauses contractual interest, legal deadlines or a formal claim. Construction and other regulated payment disputes may involve additional rules and urgent time limits. Have formal documents reviewed promptly rather than relying on a general negotiation checklist.
A practical example
Illustration: A supplier claims an additional fee for installing ten outlets instead of six. The customer accepts that four more were requested but disputes the labour rate and says two outlets failed testing. The schedule separates approval of quantity, agreement on price and the defect evidence. That is more useful for negotiation than saying the entire invoice is “unauthorised”.
What should professional help involve?
Bring the schedule and original documents to the review. Ask for an assessment of the contractual position, evidence gaps, urgent steps and realistic settlement options. A lawyer from an associated law firm can help draft the response; an accountant can reconcile payments and credits so that the legal discussion starts with reliable numbers.
Related guides
- Letter of Demand in Singapore: How to Write One, Who Should Sign It and the Cost
- How to Use Digital Signatures and E‑Signatures Safely in Corporate Documentation
- Summary Judgment in Singapore (2026): A Fast Route to Recover a Company Debt
Official sources
How Raffles Corporate Services can help
If you would like assistance with a business dispute or a demand against your company, email [email protected] or WhatsApp +65 8501 7133. We can coordinate relevant corporate services, tax advice and, where needed, legal assistance from advisers at associated law firms. Legal advice and representation are provided by those advisers. This article is general information and does not replace advice on your circumstances.