A price-adjustment clause may require a notice before the higher invoice

The supplier cost rises before the next invoice

Your contract contains a price-review clause, so you plan to add the latest material increase to the next customer invoice. Read the required steps first. The clause may address notice, evidence and timing as well as calculation. An increased supplier invoice does not by itself show that every condition for charging the customer more has been satisfied.

Extract the actual process

Identify the relevant trigger, notice recipient, supporting documents and timing stated in the agreement. Give ambiguous wording to the lawyer rather than relying on another project's procedure. Do not invent a standard notice period or assume an email to the site supervisor satisfies the actual arrangement. Keep the clause and its amendments available for the review.

Use the contract guidance narrowly

Business.gov.au's contract guidance recommends considering fee review in longer contracts where costs may rise. It does not decide whether your particular increase can be passed on. Ask the adviser how the existing mechanism operates in the circumstances, including any consequence of a missed step. Avoid changing the invoice on the assumption that a general recommendation creates a contractual right.

Source: business.gov.au: Prepare a contract

Prepare the evidence the clause calls for

Gather the relevant supplier change, affected items and calculation, distinguishing a genuine input increase from a scope variation. Include only supported information and preserve the original documents. If the mechanism refers to a defined index or period, check that the evidence matches it. Do not substitute a convenient recent price movement for the contractual basis being relied on.

Keep notice separate from agreement

Retain the actual notice and evidence of delivery through the appropriate channel. Record the customer's response and any unresolved issue. Sending a notice should not be described as acceptance of the adjustment unless the reviewed arrangement supports that conclusion. Have applicable deadlines and dispute steps assessed rather than assuming routine invoice processing resolves the legal question.

Invoice on a reviewed basis

Give accounts the confirmed treatment and supporting references before changing the charge. Keep disputed or conditional amounts clearly identified for advice. The purpose is to connect the contractual mechanism, the required communication and the invoice, so a legitimate cost concern does not become an avoidable dispute caused by skipping the steps needed to explain and support it.