Billing
Retainer, time-based and milestone models with burn against the agreed volume
Marketing agencies do not fail on projects, they fail on retainers - because a retainer with no visible burn-down is a fixed fee attached to unlimited work.
You have eleven accounts on monthly retainers. Each bought an agreed volume of work; none of them experience it that way. The client thinks of the retainer as access, which means the request that arrives on the 28th feels as reasonable to them as the one on the 3rd.
Nobody is tracking burn against the agreed volume in real time, so the overage is discovered in the reconciliation - by which point the work is done, the month is closed, and there is no defensible conversation left to have. You absorb it, again, and it becomes precedent.
On top of that, every account needs a monthly report, and building eleven of them by hand is a genuine part-time job that produces nothing new. The data already exists. It is just not anywhere the client can reach.
A retainer only works as a commercial instrument if both sides can see how much of it is left. Burn tracked against the agreed volume turns the awkward end-of-month reconciliation into a mid-month conversation, which is the only version of it that is winnable.
Most retainer work repeats. Templated project structures mean month twelve is set up the same way as month one, by anyone, without a planning session that produces the same plan again.
A portal per account means the monthly "what did you do for us" question is answered continuously by data that already exists. That is the difference between reporting as a deliverable and reporting as a by-product.
If you are primarily a media-buying shop where the work is ad spend management rather than delivered projects, the delivery structure here will sit mostly unused. Your bottleneck is in the ad platforms, not the PM tool.
Yes - a client can carry an ongoing retainer and discrete projects at the same time, billed differently. If your billing is more elaborate than that (several mixed models on one account with complex proration), tools like Scoro and Teamwork have deeper financial machinery and our comparison pages say so.
No. Each client sees only their own portal. That isolation is the reason a portal is not the same thing as sharing a workspace view.
Three projects and five people on the free plan - enough to take a live client from intake to invoice before you decide anything.