How much cash should a marketing agency keep in reserve?
The standard answer is three to six months of operating expenses. For agencies it is dangerously incomplete, because a large part of the balance in the account was never yours.
Three to six months of operating expenses is the common benchmark, and it is a reasonable target — but agencies must calculate it on their own cash. A typical agency bank balance contains client media spend awaiting payment to platforms and prepaid retainers for work not yet delivered. Neither is reserve. Subtract both before measuring anything, and a great many agencies discover their real reserve is a fraction of what the balance suggested.
Why isn't your bank balance your cash reserve?
Two large categories of other people's money routinely sit in an agency's account and get mistaken for reserve.
Client media spend
If you front client advertising, money arrives from clients and leaves for platforms on different cycles. At any point the balance includes spend collected but not yet paid out. It looks like cash. It is a payable with a short fuse.
Prepaid retainers
An annual retainer invoiced in January is twelve months of obligation sitting in the account in February. Spending it is spending against work you still have to deliver, with the staff cost of that delivery still ahead of you. The deferred revenue schedule is what makes this visible; without one, the liability is invisible while the cash is extremely visible.
| Amount | |
|---|---|
| Bank balance | 480,000 |
| Less: client media collected, not yet paid out | (210,000) |
| Less: deferred revenue on prepaid retainers | (160,000) |
| Actual free cash | 110,000 |
| Monthly operating expenses | 145,000 |
| Real reserve | 0.8 months |
An agency looking at $480,000 feels comfortable. The same agency has under a month of genuine runway. This is the single most common cash misjudgement in the sector and it is invisible without the pass-through and deferred revenue both separated in the books.
Calculating the number properly
- Start with the bank balance across all operating accounts.
- Subtract client funds held — media collected and not yet spent, and any other pass-through you are holding.
- Subtract deferred revenue for work invoiced and not yet delivered.
- Subtract near-term payables — payroll, taxes, and anything due inside 30 days.
- Divide by monthly operating expenses, using fixed costs you could not switch off quickly: payroll, rent, software, insurance.
What remains is months of real reserve. Three is a sensible floor; six is comfortable. Agencies with high client concentration, project-heavy revenue or long payment terms should sit at the higher end, because their risk of a sudden gap is greater.
What drives the right target for you
| Factor | Push the target up when | Push it down when |
|---|---|---|
| Client concentration | Largest client is 30%+ of revenue | No client above 15% |
| Revenue mix | Mostly project work | Mostly contracted retainers |
| Payment terms | Net 60 or worse, or chronic late payers | Net 15–30, reliably paid |
| Fronted media spend | You front large budgets | Clients pay platforms direct |
| Team structure | Mostly salaried staff | Meaningful contractor flex |
| Seasonality | Revenue is lumpy across the year | Even month to month |
The contractor point is worth dwelling on. An agency with a flexible contractor bench can shrink cost quickly in a downturn and needs less reserve than one carrying the same capacity as salaried headcount. That flexibility is a real asset, and it is one reason how you structure and code the bench matters beyond compliance.
The forward view matters more than the ratio
A months-of-expenses figure is a snapshot, and agencies fail on timing rather than on averages. A thirteen-week cash forecast is more useful than any reserve ratio because it shows the specific week where payroll and a tax payment collide with a late-paying client.
It does not need to be sophisticated. Opening balance, expected receipts by client by week, known outgoings by week, closing balance. Updated weekly, it is the report agency owners come to rely on most, and it is the one that catches a problem while there is still time to do something about it.
The three things that most often cause a squeeze: a large client paying late, a tax instalment nobody diarised, and delivering against a retainer that was collected and spent months ago. All three are visible thirteen weeks out and invisible in a reserve ratio.
Common questions
How much cash reserve should a marketing agency have?−
Three to six months of operating expenses, calculated on the agency's own cash. Subtract client media spend being held, deferred revenue on prepaid retainers, and near-term payables from the bank balance first. Agencies with high client concentration, project-heavy revenue or long payment terms should target the higher end.
Is client ad spend sitting in my account part of my cash reserve?+
No. It is money collected on the client's behalf that is owed to advertising platforms, and treating it as reserve is one of the most common and dangerous cash errors agencies make. Subtract it before calculating anything.
Does deferred revenue count as available cash?+
No. Prepaid retainer cash represents work you still have to deliver, and the staff cost of delivering it is still ahead of you. Spending it means funding future delivery from future revenue, which works until it does not.
How do I build a cash reserve at an agency?+
Usually by improving collection before cutting cost. Shorter payment terms, invoicing on time, chasing receivables systematically, and moving clients to direct platform billing all release cash without touching the business. After that, a fixed monthly transfer to a separate account treated as non-discretionary.
What's a 13-week cash forecast?+
A rolling weekly view of opening balance, expected receipts, known outgoings and closing balance across the next thirteen weeks. It catches timing problems — payroll colliding with a tax payment and a late-paying client — that a months-of-expenses ratio cannot show.
Know what's actually yours
Client funds and deferred revenue separated from your own cash. Standard in every engagement.
Get a free books reviewGeneral information for agency owners and operators, not accounting, tax or legal advice. Figures shown are illustrative unless stated otherwise.