The role of committed costs in construction accounting

By

Josh Krissansen

Last Updated May 20, 2026

By

Josh Krissansen

On construction projects, costs are often committed well before they appear in accounts payable, making it harder to see a project’s true financial exposure. When commitments are not tracked consistently, budgets appear under control until invoices arrive, increasing the risk of budget and late-stage corrective action.

Committed costs address this gap by capturing expenses agreed through subcontracts, purchase orders, and approved variations before invoicing. By locking in the budget early, they provide a clearer view of contractual obligations and support more accurate forecasting.

In this article, we explain how committed costs work in construction accounting, how they differ from other cost types, and how project teams can use them to improve cost control, strengthen cash flow forecasting, and reduce the risk of budget overruns.

What are committed costs?

Committed costs are project expenses formally agreed through a contract or purchase order but not yet invoiced or paid. The budget is committed as soon as the agreement is signed, rather than when the invoice arrives.

For example, a structural steel purchase order, a concreting subcontract, and an approved variation for unforeseen rock excavation are all committed costs.

In Australia, committed costs sit at the intersection of project cost management and statutory payment obligations under Security of Payment legislation, meaning they carry legal weight beyond simple cost estimates.

Committed costs vs budgeted, actual, incurred costs and budget headroom

Construction cost management uses five distinct cost types, each capturing a different point in the financial lifecycle of a project obligation. Here’s how committed costs compare to other cost types across the project lifecycle.

Note that definitions can vary by contract, accounting policy, and software configuration. Be sure to align terminology with your project controls procedure.

Why committed costs matter for job costing and cash flow

Without committed cost tracking, project financials only show what has been invoiced, not what has already been agreed. This gap increases the risk of budget overruns, cash flow pressure, and work-in-progress reporting that doesn't reflect the true project position.

Accurate job costing and WIP reporting

In many organisations, committed costs are recorded alongside actuals to support job cost reporting. 

This means cost reports reflect the full contractual position at each cost code, giving project managers and quantity surveyors a reliable basis for cost-to-complete forecasting, variation pricing, and commercial decision-making throughout the project lifecycle.

Under AASB 15, committed costs need to be reviewed to determine whether they relate directly to work the project is expected to deliver in the future, or whether they should be treated as an immediate expense. In practical terms, this affects how work in progress (WIP) is reported and when profit can be recognised across the project lifecycle.

Reliable cash flow forecasting

Head contractors and subcontractors often operate on different payment cycles, as SOPA establishes statutory timeframes that head contractors must meet regardless of when they are paid by the client. Without visibility into committed costs, those obligations are difficult to forecast.

Consider a $50 million commercial office project with 30 active subcontracts. Progress claims falling due across multiple trades in the same month can represent millions in outgoings. Tracking committed costs against subcontract payment terms and claim cycles gives the finance team the data to anticipate that exposure and plan accordingly.

Early detection of overruns

Comparing committed costs against budget on a weekly or monthly cadence allows teams to identify over-commitment before work commences, rather than after invoices are received.  Where commitments exceed budget, teams can re-scope, renegotiate, or seek client approval for additional budget while options are still available.

Stronger subcontractor payment compliance

Visibility into committed costs enables head contractors to meet statutory payment obligations on time. Under SOPA, failure to pay subcontractors within prescribed timeframes can lead to adjudication claims, suspension of works, and reputational or credit impacts.

Tracking commitments against subcontract payment terms and retention release dates reduces that exposure, turning payment compliance from a reactive problem into a managed process.

Best practices for tracking committed costs

Committed cost tracking works best when procurement, quantity surveying, and site teams are feeding the same cost register. The following practices help teams do this consistently across the project lifecycle.

Centralise contracts and subcontracts

Store all executed subcontracts and head contracts in a single, accessible location, whether a digital repository or project management platform. Record the contract value, scope, payment terms, retention percentage, and key milestones for each.

Centralising this information ensures all contractual obligations are visible to the full project team, reducing the risk of missed commitments and duplicate data entry.

Capture approved variations

Log approved variations as committed costs immediately upon approval, even before formal execution or invoicing. This ensures the cost register reflects the project’s current contractual position in real time.

Unapproved variations and claims should be tracked separately as contingent committed costs and disclosed in cost reports with appropriate risk weighting. They are not commitments until approved, but they represent real exposure that needs to be visible.

Log all purchase orders to budgets

Issuing a purchase order is what turns a procurement decision into a committed cost. Without it, the obligation sits outside the committed cost register, creating a gap between contractual commitments and reported costs.

Issue purchase orders for all material and equipment procurement above your organisation's threshold.  Ensure each is coded to the correct cost code, work package, and budget item, with GST treatment specified as inclusive or exclusive to maintain consistent cost reporting.

Long-lead items such as structural steel, façade systems, and lifts should be committed as soon as the purchase order is issued, even when delivery is months away. Early commitment locks in price and confirms material availability, reducing exposure to lead time blowouts and market price movements that can destabilise the budget late in the programme.

Reconcile site dockets and unposted payroll

Site dockets and unposted payroll sit outside the formal committed cost register in most organisations, but they still represent near-term costs that can distort forecasts if left unreconciled.

Whether they are treated as commitments or accruals depends on your controls and accounting method. What matters is that they are captured and reconciled regularly.

• Site dockets: Capture credit card purchases, petty cash, and supplier deliveries via mobile app or digital repository, code to the correct cost code, and reconcile weekly against credit card statements and purchase orders.
• Unposted payroll: Track labour hours via timesheets, calculate the cost obligation including on-costs such as superannuation, workers' compensation, and payroll tax, and record as a committed or accrued cost depending on organisational policy.

Review and true-up weekly

Without active maintenance, the committed cost register drifts from reality. Commitments get missed, approved variations go unlogged, and cancelled contracts remain open, overstating obligations and distorting forecasts.

A regular review cadence reconciles what is in the register against what has actually been executed, approved, or cancelled during the period. Each review should cover:

• New subcontracts and purchase orders issued during the period
• Variations approved but not yet logged
• Commitments to be released for cancelled or completed contracts
• An updated forecast final cost based on current commitments and cost-to-date

Involve the project manager, quantity surveyor, and commercial manager to ensure site and office data are aligned, and coding errors or missing documentation are caught early.

Implementing committed cost tracking with connected construction tools

Spreadsheet-based committed cost tracking breaks down quickly on active commercial projects. Version control issues and coding errors accumulate across teams working from different files, and by the time discrepancies surface in the cost report, the damage is already done.

Connected construction tools solve this by centralising contracts, purchase orders, variations, and site data in a single platform, giving all project stakeholders a shared view of committed costs in real time and reducing the information gaps and missed commitments that distort forecasts.

When evaluating platforms for committed cost tracking, look for:

• Automated PO-to-commitment conversion
• Multi-tier approval workflows
• Commitment vs budget variance alerts
• Integration with accounts payable systems
• Variation tracking
• Commitment release protocols for cancelled or completed contracts
• Mobile site receipt and delivery docket capture
• Portfolio-wide visibility for clients and CFOs
• Automated checks that flag duplicate purchase orders, missing documentation, unusual line items, and over-commitment risks
• GST-inclusive and exclusive tracking, retention trust account flagging for Queensland and Western Australia, and SOPA-compliant progress claim workflows

When implementing connected construction platforms, technology supports the process, but outcomes still depend on how well teams adopt and maintain it. Outcomes depend on process adoption, data discipline, and governance.

The best practices discussed above give a connected platform its value: timely purchase order issuance, consistent cost coding, and a weekly reconciliation cadence.

Committed costs improve visibility and cost control early

Tracking costs at the point of commitment, rather than at invoice, gives project teams a clearer view of their financial exposure. This supports more accurate forecasting, stronger cost control, and fewer surprises later in the project.

Written by

Josh Krissansen

78 articles

Josh Krissansen is a freelance writer with two years of experience contributing to Procore's educational library. He specialises in transforming complex construction concepts into clear, actionable insights for professionals in the industry.

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