Agencies and professional services firms have a specific accounting problem: the thing you sell is time, and time does not arrive in the bank in the same shape it left the building. Work happens in one month, gets invoiced in another, and gets paid in a third, and the books have to hold all three at once without either flattering or understating the business.
Three things drive most of it. Revenue should follow delivery rather than invoicing, pass-through costs are not revenue, and utilisation is the number that predicts whether you make money.
Revenue follows the work, not the invoice
If you invoice a retainer upfront, that is not revenue yet. If you complete a phase of a project and invoice next month, the revenue belongs to the month you did the work. Both situations create a balance that carries between periods.
| Situation | What sits on the balance sheet |
|---|---|
| Invoiced upfront, work not yet done | Deferred revenue, a liability |
| Work done, not yet invoiced | Work in progress or unbilled revenue, an asset |
| Milestone billing on a long project | Both, at different points in the project |
| Retainer with unused hours | Depends on whether unused time rolls over or expires |
Firms that recognise revenue on invoicing get books that look lumpy and reward the wrong behaviour, since a heavy invoicing month reads as a great month regardless of whether the work behind it was profitable. It also makes month-to-month comparison meaningless, which is exactly what you need for pricing decisions.
Pass-through costs are not revenue
This one distorts more agency P&Ls than any other single item. If you buy $50,000 of media, contractor time or software on behalf of a client and rebill it, running that through revenue makes the firm look much larger and much less profitable than it is.
A firm doing $2 million of its own fee income plus $3 million of rebilled media is not a $5 million business with a 20% margin. It is a $2 million business with a 50% margin and a lot of cash moving through it. Those are completely different companies to run, price and value.
Whether you present pass-throughs gross or net turns on whether you control the service before it transfers to the client, which is a genuine judgment. What is not optional is tracking net fee income separately, because that is the number your margins, your pricing and your capacity planning should be built on.
Utilisation is the number that predicts profit
In a people business, the ratio of billable to available hours drives almost everything downstream. A firm can grow revenue while quietly becoming less profitable, and utilisation is where that shows up first.
- Utilisation: billable hours divided by available hours, per person and per team.
- Realisation: what you actually billed against what you could have billed at standard rates. This is where scope creep and write-offs become visible.
- Effective hourly rate: project fee divided by hours actually spent, which is the honest measure of whether a fixed-fee engagement worked.
- Project margin after all directly attributable time and cost, calculated per project rather than as a firm-wide average.
Effective hourly rate is the one most worth calculating retrospectively on fixed-fee work. It routinely reveals that the largest client is the least profitable, which is not a conclusion anyone reaches from the revenue number alone.
How to set it up
- Run accrual accounting, so revenue lands in the month the work happened.
- Track time against projects even on fixed-fee work, because without it you cannot compute effective rate or project margin.
- Separate net fee income from pass-through costs in the chart of accounts from the start.
- Maintain deferred revenue and unbilled work-in-progress schedules that reconcile to the ledger monthly.
- Report project margin and utilisation alongside the P&L, since the P&L alone will not tell you which work to sell more of.
Cash flow is a separate problem
Agency accounting can be entirely correct and the business can still run out of money, because payroll is weekly or monthly while client payment terms are thirty, sixty or ninety days. You are financing your clients, and the faster you grow the more you finance.
This is why a growing agency often feels tighter than a flat one. Winning a large client means paying the team to deliver months before the invoices clear. Track collections and days sales outstanding alongside the P&L, and treat a rising DSO as an early warning rather than an administrative annoyance. A 13-week cash flow forecast is the standard tool for exactly this shape of problem.
Where Zinance fits
Zinance runs books for professional services firms with the structure this requires: accrual revenue tied to delivery, pass-throughs separated from fee income, and margin reported per project rather than in aggregate. Books close daily, so a project going wrong is visible while you can still act on it. See our work with professional services firms.