How to Quote Extra Work on a Fixed-Price Project

First classify the work

Read the agreed deliverables, acceptance criteria, revision allowance and any change process. Then compare the request with those boundaries.

The table is a workflow, not a determination of legal entitlement. Keep the original requirement and the new request in the same record so the conversation stays specific.

Price the whole change

Estimate production, coordination, testing, revised documentation and relevant purchased items. If your rate already includes general overhead, do not automatically add an “admin multiplier” as well. Include genuinely additional administrative effort directly.

Worked example: A website client requests a new resource library outside the agreed page list. Your proposed addition includes eight production hours, one coordination and testing hour, and a $75 asset license.

The $100 is an illustrative selling rate, and the $75 is an illustrative purchase allowance. State how any variation in that allowance will be approved. Nine hours of extra work may also move the delivery date, depending on the schedule and dependencies.

Send a decision-ready change proposal

Sample wording for this worked example:

The proposed resource library adds a deliverable beyond the five pages in our current scope. I can add it for $975, covering the build, coordination and testing, and the stated asset allowance.

The revised delivery date would be [date], provided I receive [materials] by [date]. Please confirm approval through [agreed process] before I schedule this addition. We can also keep the original scope and date.

If budget is fixed, consider replacing an undelivered item with the new request. Estimate the remaining work removed, not its original headline price, especially if part has already been completed. Record the substitution so both parties know what will no longer be delivered.

Handle work already completed differently

If extra work is finished without a clear approved charge, collect the scope, messages, time records and invoices before discussing payment. Explain what changed and ask to resolve any ambiguity. Do not present a calculator's “lost revenue” output as proof that the client legally owes that amount.

For a material dispute, advice depends on the agreement and jurisdiction. Preserve the record and get advice specific to those facts instead of relying on a generic clause or retroactive surcharge.

You can also decide to absorb a clearly identified item as goodwill. Record the time and the one-time decision internally. There is no universal rule that every request under five hours must be free.

Make future decisions easier

For the next project, specify outputs, revision rounds, client responsibilities, approval authority and what counts as completion. Budget reasonable uncertainty within the original scope. Keep new requested deliverables visible even when a small addition is included without charge.

Monitor requests as they arrive. Waiting for an arbitrary overrun threshold can mean the work is already done before anyone discusses the price.

The scope-creep calculator values excess hours using a target rate; that is a planning benchmark. For a completed-job diagnosis, see what extra hours cost on a fixed fee.