Contents
- Why does a profitable agency run short of cash?
- What does the gap look like at a $2.4M agency?
- How do you calculate days sales outstanding?
- How do you build a 13-week cash forecast?
- How many months of operating expenses should you keep in reserve?
- What billing changes close the gap?
- How should payment terms, late fees and collections work?
- What does growth cost in cash?
- When should you use a line of credit?
- What should you do this month?
- An agency pays its team every 14 days and gets paid 40 to 60 days after the work, so profit and cash drift apart as the agency grows.
- A $2.4M agency at 18% net margin with retainers billed in arrears, net 30 terms and $80,000 a month of fronted media came within $10,400 of missing payroll in one quarter.
- Billing retainers in advance on the 1st, taking project deposits and moving media to prepayment released roughly $475,000 once phased in, enough for a reserve of more than three months of operating expenses.
Cash flow management for agencies comes down to one mismatch: payroll goes out every 14 days, and client money arrives 40 to 60 days after the work. A profitable agency runs short of cash when it bills in arrears, offers net 30 to net 60 terms, fronts media spend or grows quickly, because every one of those pushes cash further behind the profit the P&L reports.
This guide works through a fictional 20-person agency doing $2.4M a year in fees at an 18% net margin that still came within $10,400 of missing payroll. It covers how to measure the gap, how to forecast it 13 weeks out, and which billing changes close it for good.
Why does a profitable agency run short of cash?
Profit is recorded when the work is done. Cash arrives when the client pays. For a product company the gap is a few days. For an agency it is routinely two months, and five things widen it.
| Cause | What happens to cash | Typical size of the gap |
|---|---|---|
| Payroll every two weeks | 26 runs a year, and two months a year carry three runs instead of two | An extra full payroll run, twice a year |
| Net 30, 45 or 60 terms | Cash arrives 40 to 70 days after the invoice once clients pay a little late | One to two months of revenue sits in receivables |
| Media and pass-through float | The agency pays the platform now and the client reimburses later | One month of media spend or more, at zero margin |
| Project work billed on completion | Six weeks of delivery, then an invoice, then net 30 | Up to three months of project cost carried before any cash |
| Growth | New hires are paid from day one, the new client pays two months later | Roughly two months of the new retainer per new client |
None of these shows up on the P&L. A three-payroll month looks normal on an accrual statement. The bank sees all three runs inside 30 days.
Pass-through costs surprise owners most. Media spend never appears in net margin, yet it moves through the bank in larger amounts than most retainers.
What does the gap look like at a $2.4M agency?
The example agency has 20 people and $200,000 a month of fee revenue: $150,000 from 10 retainers and $50,000 from project work. It also runs $80,000 a month of client media through its own ad accounts and reimburses itself by invoice.
| Line | Monthly | Notes |
|---|---|---|
| Retainer revenue | $150,000 | Invoiced on the last day of the month, net 30 |
| Project revenue | $50,000 | Invoiced on delivery, net 45 |
| Fee revenue | $200,000 | $2.4M a year |
| Payroll, fully loaded | $130,000 | Paid every 14 days, $60,000 per run |
| Overhead | $34,000 | Rent, software, insurance, professional fees |
| Net profit | $36,000 | 18% net margin |
| Media fronted for clients | $80,000 | Reimbursed at net 45, not revenue |
| Opening cash | $125,000 | Under one month of expenses |
Net margin of 18% sits inside the 15 to 25% target. The weak point is cash: $125,000 covers about three weeks of outgoings.
At the start of the quarter the agency signed a new $25,000 a month retainer and hired two people to deliver it, at $9,000 a month fully loaded each, starting in week 3. Each payroll run rose from $60,000 to $68,300. That decision was correct on margin. It nearly broke the bank account.
How do you calculate days sales outstanding?
Days sales outstanding (DSO) is how many days of revenue are sitting in unpaid invoices. The formula is accounts receivable divided by revenue for the period, multiplied by the number of days in the period.
| Input | Example agency |
|---|---|
| Retainer receivables, paid on average 40 days after invoice | $200,000 |
| Project receivables, paid on average 52 days after invoice | $87,000 |
| Fee receivables at quarter end | $287,000 |
| Fee revenue for the quarter | $600,000 |
| Days in the quarter | 90 |
| DSO | $287,000 ÷ $600,000 × 90 = 43 days |
Calculate DSO on fees only and track media float separately, or the media hides the fee picture.
DSO starts counting at the invoice, which is why it understates the problem for an agency that bills in arrears. Work done on the 1st of the month is invoiced on the 30th and paid around day 70. The month of unbilled work before the invoice is cash the agency has spent on payroll and not yet asked for.
| DSO | What it means for a retainer agency |
|---|---|
| Under 30 days | Billing in advance, short terms, card or bank transfer on file |
| 30 to 45 days | Typical. Payroll is partly funded by the agency's own cash |
| 45 to 60 days | Every payroll run is funded from reserves for weeks at a time |
| Over 60 days | A collections problem as well as a terms problem |
Read DSO monthly and watch the direction more than the level. A DSO that rises five days in a quarter on $200,000 a month of fees has quietly moved about $33,000 out of the bank and into clients' hands.
How do you build a 13-week cash forecast?
A 13-week forecast is a week-by-week list of cash in and cash out for one quarter, rolled forward every Monday. Thirteen weeks is long enough to see a three-payroll month and a slow-paying client coming, and short enough that every number in it is a known invoice, a known run or a known bill.
Keep it in cash terms only, with no accruals. Enter each client invoice and media reimbursement on the date that client actually tends to pay, not the due date. Enter payroll on the exact run dates, including taxes and benefits, and overhead and fronted media on the dates they leave the account.
Here is the example agency's quarter, in thousands of dollars.
| Week | Fees in | Media reimbursed | Payroll | Overhead and media paid | Ending cash |
|---|---|---|---|---|---|
| 1 | 35 | 0 | 60.0 | 8 | 92.0 |
| 2 | 20 | 0 | 0 | 88 | 24.0 |
| 3 | 15 | 80 | 68.3 | 8 | 42.7 |
| 4 | 60 | 0 | 0 | 8 | 94.7 |
| 5 | 70 | 0 | 68.3 | 8 | 88.4 |
| 6 | 10 | 0 | 0 | 88 | 10.4 |
| 7 | 15 | 80 | 68.3 | 8 | 29.1 |
| 8 | 55 | 0 | 0 | 8 | 76.1 |
| 9 | 95 | 0 | 68.3 | 8 | 94.8 |
| 10 | 20 | 0 | 0 | 88 | 26.8 |
| 11 | 20 | 80 | 68.3 | 8 | 50.5 |
| 12 | 90 | 0 | 0 | 8 | 132.5 |
| 13 | 105 | 0 | 68.3 | 8 | 161.2 |
The quarter has seven payroll runs, one more than two per month, and three weeks where $80,000 of media leaves the account before the matching reimbursement arrives.
Show the numbers
| Ending cash | |
|---|---|
| W1 | $92,000 |
| W2 | $24,000 |
| W3 | $42,700 |
| W4 | $94,700 |
| W5 | $88,400 |
| W6 | $10,400 |
| W7 | $29,100 |
| W8 | $76,100 |
| W9 | $94,800 |
| W10 | $26,800 |
| W11 | $50,500 |
| W12 | $132,500 |
| W13 | $161,200 |
The P&L for this quarter shows more than $100,000 of profit. The bank finishes $36,200 higher than it started, and in week 6 it holds $10,400 with a $68,300 payroll due the following week. It is met only because one media reimbursement lands in week 7. If that client pays a week late, payroll is short.
The difference went into receivables on the new retainer, the seventh payroll run and media fronted for clients. None of it is lost. All of it is unavailable.
How many months of operating expenses should you keep in reserve?
Two to three months of total operating expenses is the common rule of thumb for service businesses. It fits agencies because nearly all the cost is payroll that is due regardless of what clients do. A lost client takes a quarter to replace, and the reserve buys that quarter without layoffs.
| Reserve level | Example agency, at $182,000 a month after the new hires | What it covers |
|---|---|---|
| Under 1 month | Below $182,000 | Timing only. One late client is a crisis |
| 1 month | $182,000 | A bad month, not a lost client |
| 2 months | $364,000 | Losing a mid-sized retainer while the pipeline replaces it |
| 3 months | $546,000 | Losing the largest client, or a slow quarter of sales |
Hold more when revenue is concentrated. If one client is more than a quarter of fees, the realistic downside is losing a quarter of revenue at once, and the reserve should sit at three months or above. Hold less only when the retainer book is long, diversified and billed in advance.
Build the reserve from the billing changes below before building it from profit. The example agency already has the money. It is sitting in its clients' bank accounts.
What billing changes close the gap?
Four changes do most of the work. Each one releases cash once, as it is phased in, and keeps it released permanently.
| Change | Before | After | Cash released once phased in |
|---|---|---|---|
| Bill retainers in advance on the 1st, net 7 | Invoiced month end, net 30, paid around day 70 from the start of the work | Invoiced on the 1st, paid around day 10 | About $300,000 |
| Take a 50% deposit on project work | Invoiced on delivery, net 45 | Half on signing, balance on delivery at net 15 | About $60,000 |
| Move media to client cards or prepayment | Agency fronts $80,000 a month, reimbursed about five weeks later | Client pays the platform, or prepays the month | About $90,000 |
| Late fee plus a fixed collections cadence | Clients pay about 10 days past due | Most pay within 3 days of due | About $25,000 |
| Total | About $475,000 |
Billing retainers in advance is the largest by far. A retainer reserves the team's capacity, so the invoice goes out on the 1st and the paid invoice starts the work. Moving from arrears at net 30 to advance at net 7 shifts collection by roughly two months of retainer revenue. In practice clients move at renewal, so the release arrives over two or three quarters, not in one week. The mechanics of the advance invoice, the usage statement and overages are in how to invoice retainer clients. For a drawdown retainer, advance billing also means the client has paid for the hours before they are drawn.
Deposits stop the agency funding six weeks of delivery. A 50% deposit on signing is common, and few clients push back when it is in the proposal from the start. On builds longer than eight weeks, bill in milestones.
Media is the cheapest change to make. The agency earns nothing on the spend, so fronting it is pure lending. Put the client's own card on the ad accounts, or invoice the month's media in advance and launch once it is paid.
How should payment terms, late fees and collections work?
Terms are a pricing decision, and they belong in the proposal, not the first invoice. Clients with formal procurement who refuse net 7 will usually accept net 15 on a predictable schedule.
Put a late fee in the contract and apply it. 1.5% per month on balances more than 30 days past due is a common figure, and the cap varies by state, so confirm the limit where your contracts are governed. Most agencies rarely collect the fee. Its value is that it moves the agency's invoice up the client's AP queue.
Run collections on a fixed schedule, not when the bank looks thin: a reminder before the due date, an overdue notice the day after, a call at day 15, a written pause notice at day 21 and a pause on new work at day 30. The schedule matters more than the tone. A client who knows the day-21 notice always arrives pays before day 21.
Name who owns each step, usually the account manager for the call and the owner for the pause notice. Receivables with no owner age.
What does growth cost in cash?
Growth consumes cash before it produces any. Every new retainer billed in arrears at net 30 ties up roughly two months of its fee in working capital, permanently, for as long as the client stays. At the example agency the new $25,000 retainer ties up about $46,000: around 40 days of receivables plus half a month of unbilled work at any point in time.
Hiring ahead adds to it. The two hires cost $18,000 a month from week 3, and the client's first payment arrived in week 9: about $25,000 of payroll paid before a dollar came in.
| Growth step | Cash needed, billed in arrears at net 30 | Cash needed, billed in advance at net 7 |
|---|---|---|
| New $25,000 retainer, working capital | About $46,000 | Close to zero, the client pays first |
| Two hires starting before the first payment | About $25,000 | About $8,000 |
| Total cash to take on the client | About $71,000 | About $8,000 |
This is why fast-growing agencies run out of money more often than slow ones. Adding four new retainers a quarter on arrears terms needs close to $300,000 of cash the P&L never mentions. On advance terms, the clients fund their own growth.
Hire when the work is contracted and the cash is in the forecast, not only when utilization says so. The capacity triggers, a department at 85% utilization or above for two months, are in when to hire at a marketing agency. Add one more check: the 13-week forecast still clears one payroll run every week with the new salary in it.
When should you use a line of credit?
A line of credit is a tool for timing, not a plan for funding the business. Use it for a gap the 13-week forecast shows closing, such as a $90,000 receivable due in week 8 with payroll in week 7. Draw, repay when the receivable lands, pay a few weeks of interest.
Size it at around one month of operating expenses, about $180,000 for the example agency, and open it while the agency is profitable and the balance sheet looks good. Banks lend most readily to agencies that do not need the money yet.
The warning sign is a line that never returns to zero. Drawn for two consecutive quarters, it is funding payroll, and the cause is in the terms: arrears billing, long net days or fronted media. Borrowing treats the symptom at interest. The billing changes treat the cause for free.
What should you do this month?
- Calculate DSO on fees for the last quarter, and separately total the media and pass-through money currently owed to the agency.
- Build a 13-week forecast with every payroll run dated, and mark every week where the ending balance falls below one run.
- Total monthly operating expenses and set a reserve target of two to three months. Write down the gap between that and today's cash.
- Move the next retainer that renews to advance billing on the 1st at net 7, and put a 50% deposit in the next project proposal.
- Ask every client running media through the agency to put their own card on the ad account or prepay the month.
- Add a late fee clause and a dated collections cadence to the contract template, and name who owns each step.
Track DSO and months of reserve alongside the other operating numbers in marketing agency KPIs and benchmarks. Verbial carries each deal from signed proposal to invoice and payment, and shows margin per client from contracted revenue and retainer pacing while the month is running, so the forecast starts from real invoices.