A 13-week cash flow forecast for contractors

Why 13 weeks

Profitable home service companies still run out of cash. Equipment is bought before the install is paid for, commercial customers take 45 days, payroll lands every Friday and the insurance premium arrives in one lump. In the 2025 Small Business Credit Survey, 50% of small employer firms reported uneven cash flow as a financial challenge, a category that includes collecting on receivables^[1].

A 13-week forecast is a rolling, week-by-week view of the next quarter. Thirteen weeks is long enough to catch the slow-season dip, a big supplier bill or a quarterly tax payment before it arrives, and short enough that you can forecast with real numbers: the jobs on the board, the invoices outstanding and the bills you know are coming. Beyond that horizon, an annual budget does the job better.

When cash ran short, firms in the same survey most often used personal funds, raised prices, drew on cash reserves or cut costs, and 24% made a late payment or did not pay^[1]. A forecast is how you choose your response in advance instead of finding out on payroll day.

The template structure

Use one column per week, starting on the same weekday every time, and these rows from top to bottom. A spreadsheet is fine; the structure matters more than the tool.

Add a minimum cash line: the balance below which you will not let the account fall, usually at least one payroll plus a cushion. Every week where closing cash is forecast below that line gets highlighted. Below it, add the undrawn balance on any credit line, so you can see how much room you really have.

Getting the inputs right

The forecast is only as good as its receipts. Payments out are easy to predict because you control them; money in depends on customers. Build receipts from three sources.

• Existing receivables: list every open invoice with the date you realistically expect payment, based on that customer's history rather than the due date. A property manager who always pays in 52 days goes in week 8, not week 5. Our guide to collecting from commercial clients helps shorten that.
• Booked work: for the next two to three weeks, use actual jobs on the schedule. Multiply by your average invoice and the share collected on the day, then put the rest in the week those customers usually pay. Homeowner financing shifts timing too: only 63% of US adults say they would cover a $400 emergency expense entirely with cash or its equivalent^[2], so large repairs paid through a finance company arrive when the lender funds, not when the tech finishes.
• Expected new work: beyond the booked horizon, use last year's revenue for the same weeks, adjusted for this year's trend. Be conservative; it is better to be pleasantly surprised.

For payments, use your payroll calendar exactly, including the months with three biweekly paydays, the week commissions are paid and the quarter-end payroll tax deposits. Put annual items such as insurance premiums, vehicle registrations and software renewals in the week they will actually be charged. These lumpy items cause most surprises.

Seasonality changes everything

Seasonal trades need the forecast most. Landscaping services employment in the US rose from 756,000 in January 2025 to 1,014,200 in July 2025, a 34% swing^[3]. Landscaping firms paid only 19.3% of their 2023 annual payroll in the first quarter, against 25.9% across all industries^[4]. Revenue swings harder than payroll does, which means cash often runs lowest just as the season starts: crews are hired and trained, equipment is serviced and materials are bought before the first spring invoices are paid.

HVAC companies feel the same squeeze at the start of the cooling season when equipment orders spike. Roofers see it after storms, when material costs arrive before insurance-funded payments. For these businesses, the most useful forecast is the one you start in late winter, covering the ramp into the busy season.

The weekly routine

1. 01

   Roll forward

   Drop the week just finished and add a new week 13 at the end, so the forecast always covers the next quarter.

2. 02

   Enter actuals

   Replace last week's forecast with what actually happened: real bank balance, real receipts, real payments.

3. 03

   Explain the variance

   For any line off by more than a set amount, write one line saying why. A customer paid late, a job slipped, an unplanned repair. The notes are how the forecast gets better.

4. 04

   Update the next four weeks

   Refresh collections from the AR aging and new work from the schedule. Weeks five to thirteen change less often.

5. 05

   Check the minimum cash line

   List any week that falls below it and decide what you will do, with a name and a date beside each action.

6. 06

   Share it

   Send a one-line summary to the people who need it: the owner, the office manager and the bookkeeper.

The whole routine takes about 30 minutes once the template is built, usually on Monday morning before the week's purchasing decisions. Keep it tied to the monthly close in your bookkeeping routine so the forecast starts from reconciled balances.

Example: a roofing company heading into spring

Example (fictional): a roofing company starts week 1 on March 2 with $142,000 in the bank and a minimum cash line of $60,000, roughly one payroll plus a cushion. Payroll runs $38,000 every other Friday. Spring material orders of $95,000 are due in weeks 4 and 5, and the annual general liability premium of $31,000 lands in week 6.

Example receipts: existing invoices and retail jobs paid on completion are expected to bring in $139,000 over weeks 1 to 6, net of rent, fuel and other routine bills. Booked insurance replacement jobs start in week 3, but insurance-funded customers usually pay three to five weeks after completion, so most of that cash lands in weeks 7 to 10.

Example result: the forecast shows closing cash falling to $41,000 in week 6, below the $60,000 line, then recovering to $118,000 by week 10. The owner now has five weeks to act. She asks the supplier to split the material order into weekly deliveries tied to job starts, collects deposits on the two largest retail jobs, moves the premium to monthly installments and confirms the credit line has $75,000 available as a backstop she should not need.

What to do when the forecast shows a gap

Work through these in order, starting with the options that cost nothing.

1. Speed up collections: call the largest overdue accounts, send invoices the day the job finishes and offer customers a way to pay online. Our guide to text-to-pay and online invoices covers the setup.
2. Take deposits on installs and large repairs where your contracts allow it.
3. Time purchases to jobs: order materials for specific starts rather than stocking up early.
4. Move lumpy bills: ask insurers and software vendors about monthly payment plans.
5. Delay discretionary spending: equipment upgrades and owner draws can usually wait a few weeks.
6. Use credit last, and only for a gap you can see closing in the forecast. Borrowing to cover a gap that never closes only postpones the decision.

If the forecast shows a gap every quarter, the problem is not timing. Revisit your break-even analysis and your overhead: the business may need higher prices or lower fixed costs, not a bigger credit line.

Mistakes that make forecasts useless

The most common is forecasting from invoices instead of payments. An invoice is a promise; the forecast only counts the week the money arrives. The second is optimism: treating every estimate as a sale and every customer as an on-time payer. The third is never comparing forecast with actual, which means the same mistakes repeat every week. Finally, keep personal and business accounts separate. A forecast that has to guess at the owner's personal spending through the business account cannot be trusted by anyone, including the owner.