Time and Materials with a Not-to-Exceed Cap

A time-and-materials arrangement with a not-to-exceed amount combines a billing calculation with a ceiling. Under the illustrative terms here, eligible hours and expenses are billed until the cap is reached. The cap limits modeled revenue; it does not automatically limit the hours needed to finish the work. The actual agreement must establish scope, approvals, and what happens near the limit.

Calculate the cap before estimating the result

Assume a hypothetical client rate of $120 per eligible hour, $1,000 of reimbursable project expenses, and a $12,000 total cap that includes those expenses. Internal delivery cost is $55 per hour, and the $1,000 expense is also a real business cost. With 100 hours delivered, uncapped charges would be $13,000, but billable revenue is limited to $12,000 under these entered terms.

After the $1,000 expense allowance, the cap leaves $11,000 for time charges. At $120 per hour, it covers 91.6667 hours before any time-billing increment is applied. That fractional threshold should be checked against the actual invoice convention. It is not 100 fully billable hours merely because the cap divided by the hourly rate equals 100; expenses consume part of the same cap.

Forecast remaining effort before the ceiling is reached

At 80 completed hours, the eligible charges are $10,600 and cap headroom is $1,400. If 20 hours remain, they would normally generate $2,400 of time charges, exceeding the headroom by $1,000. Their internal cost is $1,100. Under an unchanged cap, those 20 hours add only $1,400 of revenue and $300 to the modeled result.

A further 20 hours after that would add $1,100 of cost with no additional billable revenue under this simplified scenario. The example makes the commercial exposure visible; it does not establish that work must continue without approval or that the provider may stop unilaterally. Follow the actual change and authorization process.

Keep the cap definition precise

Record whether the limit includes expenses, third-party work, discounts, or particular workstreams. A limit applying only to professional fees produces a different calculation from a limit on the entire invoice. If the scope changes, show the approved revision separately rather than assuming the original cap rises automatically.

Track actual eligible time, excluded time, incurred expenses, and independently estimated remaining effort. Zero hours can still produce expense charges if the entered terms permit them. A cap below already incurred costs can produce a negative project result, which should not be hidden. This is a planning model for supplied terms, not a legal interpretation, a guaranteed hourly realization rate, or an assurance that the work can be completed within the ceiling.

Method references: OpenStax: Prepare Operating Budgets. Accessed October 22, 2026. All dollar figures are hypothetical worked examples.