How agency retainers work, and how to structure one

How does an agency retainer work?

Each month the client pays the agreed fee, and you deliver what the agreement says that fee buys. The month then resets, and the cycle starts again.

A typical month on a retainer runs like this:

1. The fee is billed at the start of the month, or on the date you agreed.
2. You plan the month's work with the client, from the list or the hours the retainer covers.
3. You deliver and report, so the client can see what the fee paid for.
4. You review together, and adjust next month's plan if their goals have moved.

Write down the monthly scope, the price and the due dates, so both of you know what one month includes. The fee comes from your costs and the hours the work takes. For working out the monthly fee, see how to set a retainer fee.

Which agency retainer model fits your work?

The model that fits is the one that matches how your client's work arrives: as a known list, as a steady flow of hours or as help on call. Here's how three common models compare:

To pick one, ask three questions:

• Can you list the work in advance?
• Does the client care more about what gets done or about the time spent?
• How much does the workload swing from one month to the next?

Picking a retainer model comes after choosing to charge by the month at all. For the pricing models side by side, see agency pricing models.

In our view, a retainer is also a natural home for added services that earn without eating into your own hours. The Tobie Group shows how that can play out. It started as an agency focused on paid advertising, and as its clients asked for landing pages, custom builds and harder technical work, its founder, who isn't a developer, became the bottleneck. DeskTeam360's team took on that build work, everything from landing pages up to advanced development. The case study was posted in June 2025, and by then the two had worked together for nearly three years. The agency offered its clients website care as an ongoing monthly service, with detailed reports and regular updates. That's one agency's story, and it doesn't promise the same income for yours.

What should an agency retainer agreement cover?

A retainer agreement should cover the terms that only a monthly deal needs: the monthly scope, unused hours, the minimum term, notice to end it and when the fee gets reviewed. Settle each one before the first invoice:

• Monthly scope. What one month includes, and how extra requests get quoted.
• Unused hours or tasks. Whether they carry into next month, and for how long.
• Minimum term. How many months the client commits to at the start, if any.
• Notice. How much warning either side gives before the retainer ends.
• Fee review. When the fee is looked at again, such as once a year or when the scope changes.

If you sent a proposal first, the agreement should match what it said. For the written proposal, see the marketing agency proposal template.

We don't give legal or tax advice, so check your own case with a lawyer or an accountant.