Financial model for service business: hours, rates and cash

A financial model for service business planning connects delivery capacity, billable hours and realized rates to profit, then connects invoices and collections to cash. Start with the hours your employees can actually deliver and the fees your customers actually pay. Keep revenue, billings and receipts separate so a profitable month cannot hide a collection problem.

Start with exports that share the same month

Bring an employee roster, approved timesheets, the invoice register, delivery payroll, subcontractor bills and customer receipts. Use employee and project identifiers consistently. Record the month services were delivered separately from the invoice date and payment date.

The IRS recordkeeping guide identifies sales, purchases and payroll documents as support for business transactions. Those records should support the planning assumptions too: an hourly rate without invoice evidence is a price list, not necessarily an achievable rate.

Give operations ownership of available hours and delivery requirements. Finance owns realized rates, cost classifications and collection timing. Agree whether available hours exclude holidays, leave and training before comparing utilization across teams. The distinction between utilization and realization explains why busy staff can still produce weak revenue.

Build the capacity and revenue schedule

Consider a US consulting company planning October 2026. These are supplied assumptions, not industry benchmarks. Available hours are per employee after planned absences; loaded monthly payroll includes salary, employer taxes and benefits.

Put those columns in A:F, with the first team on row 2. Add capacity in G, billable hours in H, fee revenue in I and loaded payroll in J:

G2 = B2*C2
H2 = G2*D2
I2 = H2*E2
J2 = B2*F2

Fill down through row 4. Utilization cells contain percentages. The result is:

Total utilization is =SUM(H2:H4)/SUM(G2:G4), or 74.2%, rounded to one decimal. Do not average team percentages: the teams have different capacity. Fee revenue uses realized rates after expected discounts and write-downs. For fixed-fee assignments, use contracted fees and test their required hours against this same capacity schedule.

Carry revenue into contribution and operating profit

Add the subcontractor and overhead assumptions below. Delivery payroll stays at its full planned amount, including paid hours that are not billable. This is a management contribution view; align its cost labels with the ledger before comparing it with reported gross profit.

Contribution margin is 118,640 / 280,640 = 42.3%, rounded to one decimal. The gross profit margin guide explains why consistent direct-cost definitions matter when comparing periods.

Change just consultant utilization from 75.0% to 70.0%. Consultant billable hours become 672, a decline of 48 hours. At the unchanged $180 rate, fees fall by $8,640 and operating profit becomes $40,000, with payroll, subcontractors and overhead held constant. This isolates the capacity assumption; it does not assume staff costs disappear when demand falls.

Add collections and prove the cash balance

Assume every dollar of October revenue is invoiced in October, with no unbilled work, customer deposits or credit memos. The company starts with $210,000 of receivables and expects $250,000 of customer receipts. Its opening cash is $100,000, and every expense shown above is paid during the month.

The checks are explicit:

Closing receivables = 210000+280640-250000
Closing cash = 100000+250000-146000-16000-70000

Tie closing receivables to the aging report and closing cash to the bank reconciliation. The SBA finance guide lists receivables, available cash, bank reconciliation and payroll among the finance responsibilities a business needs to manage.

Profit exceeds the cash increase because receipts lag revenue. Follow individual invoices before assuming that days sales outstanding will improve. Keep financing, equipment purchases, income taxes and owner distributions on additional cash lines when they apply; this operating example assumes none.

Where service-business planning goes wrong

• Using paid hours as billable hours. Leave, training, sales support and internal work consume capacity without necessarily producing fees.
• Applying list rates to every hour. Discounts and fee caps can make realized rates materially lower.
• Reducing payroll automatically with utilization. Salaried delivery capacity remains a cost until an actual staffing change occurs.
• Counting invoices as cash. Payment dates belong in a collection schedule, supported by open invoices and customer commitments.

Keep staffing changes, pricing changes and collection changes in separate assumptions. A broader startup financial model covers the funding context; this schedule explains the delivery economics inside it.

Check your service workbook in Covirage

Bring a sample of your own staffing workbook, timesheet export, invoices and collections file to Covirage. Covirage maps the columns, and its tools compute and check capacity, revenue, contribution and collection figures; the external AI model explains the results with every figure traced to its rows. Create a free Covirage account, then set up your business and bring your files.

See Covirage for professional services for the supporting industry context.