How to scale a marketing agency without hiring more staff

Retainers per account manager is the number that decides when a marketing agency hires, and it rises when the monthly client report, the contact report after every call and the timesheet chase come off the account manager's desk. Each retainer brings that admin every month, along with the purchase order before the invoice, and it is the admin, rather than the account manager's talent, that caps the number. An AI worker can draft the reports and chase the actions and timesheets, so each account manager carries more retainers with the same care. The ideas, the recommendation, the relationship and every word that reaches the client stay with your people.

Why is an agency's next hire in client services?

When an agency wins a retainer it rarely needs another designer or strategist straight away. It needs someone to run the account, and account managers fill up. The IPA's own description of the job is the reason: an account manager keeps accurate records of meetings, decisions and next actions, seeks approval of changes to deadlines and budgets, works with finance to limit write-offs, bill accurately and chase unpaid invoices, and keeps the agency's systems up to date. Each retainer adds all of that, every month, for as long as the client stays. At some number of accounts the account manager is doing more recording than managing, and the agency hires another. On accounts per person, Databox asked 48 agencies and reported, in an article updated in July 2025, that almost 70% had account managers handling fewer than 10 clients each. Where your own number sits depends on the fee and the service.

The margin goes at the same time. A retainer is a fixed fee against an agreed scope, and the agency only knows it has over-serviced once the hours are in. If the hours arrive after the month is over, the overrun is a write-off.

How much admin does one retainer carry?

Each retained client adds, every month, one report, a contact report after each call and each round of feedback, a timesheet chase and an invoice. The job profile for an account executive lists writing and distributing contact reports among its duties. Where the client's finance team wants a purchase order number, someone has to ask for it before the invoice goes, and with no agreed date the invoice is late, by default, 30 days after the client receives it. Then the same again for the next client.

Benchmarks for agency profitability exist, such as The Wow Company's BenchPress survey of UK agencies. The admin is much the same whatever the fee, so a small retainer carries nearly as much of it as a large one. The marketing agencies page describes each of those jobs; what matters here is what they do to the number of accounts a person can hold.

What does the account manager keep?

The thinking stays with the account manager, above all the recommendation at the end of the monthly report, which is what the client pays for. So does the sign-off of every contact report, because the account manager was in the room and the agent was not. What to do about an over-serviced retainer belongs to the account director. The pitch, the fee, the phone calls and any invoice the client disputes stay with the account manager, and the creative work itself stays with your people, out of an AI worker's reach.

Which jobs can AI staff take off an account manager?

For an agency the first role is management reporting, pointed at the monthly client report. It is specified with you, and works through the route each analytics or ad platform publishes, confirmed with you at the start. It would collect each client's agreed figures on the day you set, check them against last month, mark what has moved more than usual, and draft the report in your format. The account manager reads it, questions it, writes the recommendation and sends it.

The second is meeting follow-up and notes, which would turn the call transcript or the account executive's jottings into the contact report in your template: who was there, what was decided, what was approved, what was promised and by when. It would file the note and chase each action to its owner inside the agency. The account manager approves the note before it goes anywhere, and the record of what was agreed exists before anyone needs it.

Each of these two jobs would go to an AI worker, with a role specification, a list of what it must hand over and one person in the agency accountable for it.

Which job should an agency hand over first?

Count, for last month, how many hours client services spent building reports and writing contact reports, and how many contact reports were never written at all; that second number is the one to worry about. Then start with the monthly report, because its inputs are already in systems that publish a way in, its format is already yours and the account manager's judgement sits in one marked paragraph. Try it on two clients before the rest. Our guide to the monthly client report sets out the steps.

Add contact reports once the team is used to approving a draft rather than writing one. Timesheet chasing comes next; it is the one that moves the margin, and it works best once the reports show where the hours went. Six months on, the test is whether the same account managers hold more retainers, every call has a contact report and nobody is rebuilding a deck the night before it is due.

The argument beyond agencies is in how to scale a business without hiring more staff, and how an AI worker differs from a tool somebody has to run is in our explainer on AI staff. Our starting price is on the homepage.

At a marketing, creative or digital agency the reporting, recording and chasing around each account could come off your account managers, though never the work the client came for. Are the monthly reports eating your account managers' week? Talk to our agent.