Construction Cash Flow: How to Forecast and Manage It

Construction companies rarely fail for lack of work. They fail because cash goes out on labour, subcontractors and materials weeks or months before clients pay, and a busy year multiplies the gap. This playbook covers the routines that keep a contractor’s cash under control. For why construction cash flow works the way it does and a worked retainage example, see the construction cash flow forecast page.

Forecast job by job

Company-wide forecasts are built from project forecasts. For each active and expected job, forecast by month:

• Billings: from the schedule of values and programme
• Collections: billings less retainage, on the client’s real payment timing
• Retainage release: when you realistically expect it after completion
• Costs: labour, subcontractors, materials, equipment and permits, on their payment dates

Add the jobs together with overheads, loan payments and tax to get the company forecast. When a job slips, update its line and the whole picture moves.

The weekly routine

1. Bank balance and collections received against forecast.
2. Payment applications: which are due this week, and which submitted applications are awaiting approval?
3. Overdue payments: chase approvals and payments by name.
4. Payables: subcontractor and supplier payments due, against what’s been collected.
5. The lowest balance in the next eight to thirteen weeks.

The monthly job review

For each job, compare billed-to-date with the cost and percentage of completion:

Under-billing means work is done but not invoiced, which is cash you’re financing. Oak Street needs its next application submitted now. Over-billing brings cash in early; it’s helpful, but remember those costs are still to come.

A worked month

A contractor with four active jobs reviews the month. Collections are $38,000 below forecast because one client returned a payment application for missing lien waivers. The weekly check had flagged it as “awaiting approval” for ten days. The team resubmits with the paperwork the same day; payment arrives two weeks later than planned.

The job review shows Oak Street under-billed by $39,000, so an application goes in immediately. Retainage of $24,000 on a school project completed three months ago is still outstanding; the release conditions were met, so the contractor chases it with the client’s project manager. The company forecast, updated with these changes, still shows a dip in six weeks when two jobs mobilise together, so the second start is moved by two weeks with the client’s agreement.

Three routine actions, taken early, keep the business clear of its overdraft limit.

Billing discipline

• Submit payment applications on the first date the contract allows.
• Make them accurate and fully supported, so they aren’t sent back.
• Track each application from submission to approval to payment.
• Ask for mobilisation or deposit payments on new contracts.
• Bill stored materials where the contract permits.
• Include all required paperwork, such as lien waivers and certificates, with every application.
• Keep a named contact at each client for approvals, and escalate politely when deadlines pass.

Retainage

Keep a retainage register: amount held per job, release conditions, and expected release date. Retainage often adds up to a large share of annual profit. Chase releases as soon as conditions are met, and push back on release conditions tied to other trades’ work where you can.

Remember the other side: retainage you hold from your subcontractors is money you’ll need to pay when your own is released.

Subcontractor and supplier terms

The goal is to pay subcontractors and suppliers on terms that match when you’re paid. “Pay when paid” or “pay when certified” clauses help where they’re lawful and agreed. Negotiate longer terms with suppliers on large jobs, and avoid paying ahead of your own collections unless you’re getting a discount worth the cash.

Change orders

Unapproved change orders are one of the biggest hidden cash drains. Get written approval and a price before doing the work wherever possible, bill approved changes with the next application, and track pending changes separately. Don’t count unapproved changes as cash in the forecast.

Bidding with cash in mind

Before bidding a large job, forecast its cash profile: mobilisation costs, the first payment date, retainage, and the peak amount of your own cash it will need. Two or three large jobs starting together can need more working capital than the business has. Stagger starts, negotiate mobilisation payments, or arrange funding before you win.

Cash and the order book

A growing order book is good news, but every new job needs cash before it pays. Track the peak cash need of your current and planned jobs together, not just profit margin. If the peak exceeds your available cash and facilities, the order book is a risk, not just an opportunity.

Seasonality

In many regions, winter slows work and billing while overheads continue. Forecast the season from last year, keep part of summer’s cash in reserve, and schedule equipment purchases for when cash is strongest.

Warning signs

• Under-billings growing across jobs
• Payment applications returned or delayed
• Retainage outstanding on completed jobs
• Subcontractors asking to be paid faster, or suppliers putting you on stop
• Overdraft use rising while the order book grows
• Change orders done but not approved
• Profitable jobs finishing with less cash than expected, because costs ran ahead of billing
• Estimating and site teams unaware of payment terms on the jobs they run

When cash gets tight

1. Submit every outstanding payment application and chase approvals.
2. Chase retainage due on completed jobs.
3. Agree timing with major subcontractors and suppliers before payments are late.
4. Delay equipment purchases and non-essential overheads.
5. Consider invoice or contract finance for large approved applications.

Tools

The premium Construction template includes a Progress Billing tab that converts billings into cash collected, retainage held and retainage released, a 13-week weekly view for payroll and payment runs, scenarios, and a dashboard. See also how to forecast receivables.