The retainer client who taught us how to set boundaries

We had a client on a retainer for almost a year. Good budget, interesting work, genuinely nice people to talk to. By month four, they were calling on weekends. By month six, we were delivering work that was not in scope because it felt easier than the conversation. By month eight, we were resentful, exhausted, and doing work we were not proud of. That is not a client problem. That is a boundaries problem, and it was ours to own.
The retainer was structured loosely. A monthly fee, a general description of services, and an informal understanding that we would handle what came up. That kind of arrangement works when trust is high and expectations are calibrated. It stops working the moment one side starts pulling harder than the other expected.
Where it went wrong
The first out-of-scope request was small. A quick social media post. We did it because saying no felt disproportionate. The second was a little bigger. A landing page that was adjacent to the campaign work we were already doing. We did that too, with a note that it was a favour. By the time they were asking for strategy work that should have been a separate engagement, we had trained them that scope did not really mean anything.
We had also failed to document what was included. The original proposal was vague by design because we did not want to seem inflexible at the start of a new relationship. That vagueness became the source of every conflict we had later.
What we changed
After a difficult but necessary call, we restructured the engagement completely. We wrote a proper scope document. Hours per month, specific deliverables, a process for requesting additional work. We named a rate for out-of-scope items so there was never any ambiguity. The client agreed to all of it. They had not been trying to take advantage. They just did not know where the lines were because we had never drawn them.
The last four months of that engagement were among the best work we have done. Clear scope means clear priorities. Clear priorities mean better work. The client got more value from us when we were not spread thin across twelve things they had not formally asked for.
We now do this at the start of every retainer. The scope document is non-negotiable. The out-of-scope rate is discussed upfront. And when something comes in that sits outside the agreement, we say so immediately, not after we have already done it for free twice.
Boundaries are not about being difficult. They are about doing your best work. You cannot do that when you are guessing what the engagement actually covers.