You are not allowed to host zaps for your customers. That goes against Zapier’s terms of use. Which means that each customer needs to have their own Zapier account, and you can determine which ones need to upgrade or not on an individual basis. 

Thank you David! That’s helpful. I probably need to have a call with Zapier about this, but is it possible to create an account for each of my clients and still build and customize zaps for them and my team and I still run everything and all of the maintenance through my company? Or does the client have to go in Zapier themselves to maintain their zaps/workflows?

You can use all Premium apps under your Zapier subscription while building client workflows. But if a client needs to run those Zaps on their own account, they must also have a plan that includes access to those Premium apps. Let me know if you'd prefer to manage everything under your agency account.

Ideally I’d like to run everything under my agency account if that’s possible. Any advice?

You’d have to be a certified Solutions Partner, which then gives you access to manage and host their plans for them. But you’d still have to log into each account individually. Zapier doesn’t have agency accounts so to speak where all your customers are connected to your single account. They’re a couple years behind the times on that one.

All of the customer zaps have to be in the customer accounts with their own paid plans. But Zapier does not have any policies against sharing logins. Meaning, each customer would have to share their personal password with you, and then you can log into each of them individually. How you want to sell or manage the maintenance with your customers is up to you. But it does have to be from their accounts.