Do we need to open a separate Avast Business console for each client?

As an IT service provider, you can choose to have one Avast Business Hub console per client, or you can use the Avast Business Hub console in multi-site mode to manage all your clients from a single console.

To convert an Avast Business Hub console into a multi-site console, go to Company profile > Convert to a multi-tenant console (top right of your screen).