Subcontractor cash flow management, done right

The subs that go under are rarely the ones losing money on jobs. They are the ones who ran out of cash three weeks before a payment landed. You can be profitable on every job you run and still miss payroll, because a subcontractor pays for labour and materials now and gets paid for them 30, 60, sometimes 90 days later. That gap is the whole problem, and managing it is a different skill from winning work or running a tight crew. Cash flow management is the discipline of making sure there is money in the account on the day you need it, every week, no matter what the profit statement says.

This is not the same as getting paid faster, though that helps. Getting paid faster is about shortening the gap. Cash flow management is about surviving the gap you cannot shorten, by seeing it coming and planning for it. Here is how subs actually do that.

Profit and cash are not the same thing

A job can be profitable and still drain your bank account for months. You bill progress, hold 10% back as holdback, wait on the payment clock, and in the meantime you have already paid the crew every Friday and the supplier on net 30. Your income statement shows a healthy margin. Your bank balance shows you funding the general contractor's project out of your own pocket until the money comes back.

That is why a profit number tells you nothing about whether you can make payroll next week. Profit is earned when you do the work. Cash is real when it hits the account. The distance between those two events is where subcontractors get into trouble, and the only way to manage it is to track cash on its own, separately from profit, on a calendar.

The cash cycle: why subs are always lending money

Walk the timeline of a single job and the problem is obvious. You mobilize and pay for the first materials. You run crew for a month and pay them weekly. At month-end you issue a progress invoice. The payment clock starts, and under most arrangements you wait weeks for the money, minus holdback. Then the cycle repeats for next month while last month's cash is still outstanding.

So at any moment you are carrying weeks of labour you have paid for and not been paid back, plus materials, plus every dollar of holdback on every active job. The busier you get, the bigger that carried balance grows. Growth eats cash: a sub who doubles their work without planning the cash to fund it is in more danger than one who stays flat, which is the thing nobody tells you when the phone starts ringing.

Build a 13-week cash flow forecast

The tool that fixes this is a rolling 13-week cash flow forecast. Thirteen weeks is a quarter, far enough to see trouble coming and short enough that you can actually estimate it. You update it every week. It is the single most useful document a subcontractor owner can keep, and it lives in a spreadsheet just fine.

The idea is simple: for each of the next 13 weeks, lay out the cash you expect in and the cash you know is going out, and carry the running balance forward. The week the running balance goes negative is the week you have to act on today, not then.

Opening balance: $35,000.

The table above is the whole point: the business is profitable, but weeks 2 and 3 go negative because a big collection does not land until week 3, and it takes until week 4 to climb back out. Seeing that in week 1 gives you options, such as pulling a draw forward, delaying a non-urgent purchase, or drawing on a line of credit on purpose instead of by surprise. Seeing it in week 2 gives you a crisis.

What goes in it

Cash in is expected collections, not billings. That is the hard part: it means predicting when each invoice actually gets paid, which depends on the payment terms, the holdback, and each client's real-world habits. Pull the timing from your billing records and be honest about who pays on time. Cash out is more knowable: payroll by week, supplier payments by due date, rent, insurance, equipment, loan payments, taxes. The more of this you can read straight from your job costing and billing system instead of rebuilding it by hand each week, the more likely you are to keep the forecast current.

The levers you control

When the forecast shows a gap, you have a handful of levers, and knowing them in advance is what keeps a tight week from becoming an emergency.

Bill earlier and cleaner so collections land sooner: a proper invoice issued on the 1st with complete backup gets paid before one issued on the 20th with missing documents. We cover those tactics in the cash-flow playbook for getting paid faster. Front-load the schedule of values within reason so early draws recover mobilization costs. Match supplier terms to your collection timing, so you are not paying net 15 on materials you will not collect on until day 60. And arrange a line of credit before you need it: a bank lends to a business that is planning, not one that is panicking. The line bridges known gaps, it does not fund losses.

Holdback and retainage: money you earned but cannot spend

The most predictable drag on a sub's cash is the money withheld on every job. In Canada that is statutory holdback, usually 10%, parked until the lien period expires. In the US it is retainage, which varies by state. Either way it is cash you have earned, that you cannot touch, often for months after the work is done.

The mistake is treating released holdback as a windfall when it shows up. It is not a bonus, it is your money finally coming home, and if you have not tracked it, you will not chase it, and some of it will quietly never arrive. Track every holdback and retainage balance by job, with the date it becomes releasable, and put those release dates into the cash flow forecast as expected collections. Run your Canadian numbers in the holdback calculator and your US numbers in the retainage calculator so the amounts in your forecast are right, not guessed.

A reserve is not optional

Even a perfect forecast cannot cover the thing you did not see: a client who pays 40 days late, a job that goes sideways, a change order that takes three months to sign. A cash reserve is what absorbs that. A common target is enough cash to cover six to eight weeks of payroll and fixed overhead with zero collections, because payroll is the one bill you cannot delay and keep a crew.

Build the reserve in good quarters and protect it. The temptation when work is booming is to put every dollar back into more work, but that is exactly when the carried balance of unpaid labour and holdback is growing fastest, which is exactly when you are most exposed. The reserve is what lets you say yes to a big job without betting the company on one client paying on time. For the wider backdrop on how much construction volume swings quarter to quarter, Statistics Canada's construction data is a useful reminder that the slow stretch always comes eventually.

SubTrade was built inside a commercial subcontractor in Calgary, Alberta. Its progress billing handles holdback on every draw, so the billing numbers that feed your forecast sit in one place instead of five spreadsheets. It starts at $299/month CAD with a 14-day free trial.

FAQ

What is cash flow management for a subcontractor?

Tracking money in and money out on a calendar, separately from profit, so there is cash in the account when payroll and suppliers are due. Subs pay for work weeks or months before they get paid for it, and managing that gap is what keeps a profitable business solvent.

Why can a profitable subcontractor run out of cash?

Because profit is earned when the work is done, but cash arrives much later, after progress billing, the payment clock and holdback, while you have already paid the crew and the suppliers. A profitable job can drain your account for months before it pays you back.

What is a 13-week cash flow forecast?

A rolling projection of expected collections and known expenses for each of the next 13 weeks, with the running balance carried forward. You update it weekly. It shows you the week your balance goes negative while you still have time to act.

How much cash reserve should a subcontractor keep?

A common target is six to eight weeks of payroll and fixed overhead covered with no collections at all. Payroll is the one bill you cannot defer, so the reserve is sized to protect it through a slow or late-paying stretch.

How does holdback affect cash flow?

Holdback, and retainage in the US, is cash you have earned but cannot access, often for months. It is a steady drag across every active job. Track each balance with its release date and put those dates into your forecast so the money is chased, not forgotten.

Does getting paid faster fix cash flow problems?

It helps by shortening the gap, but it does not remove it. You will always carry some unpaid labour and withheld holdback. Cash flow management is about forecasting and surviving the gap that remains, not just closing it.