Client limit per plan

Each plan has a maximum number of active clients: Free 3, Starter 15, Pro 50, and Arnold 500. When you reach the cap, you won't be able to add more clients until you free up a spot or upgrade your plan.

To raise it, go to Settings → Billing and choose a plan with more capacity.

Keep in mind that the limit counts your active clients, so removing someone you no longer train frees up a spot.