wwaigl

I have a few presales questions, but I will ask this one first. We have several servers with 25-50 customers per server and currently we manually bill via paypal. Do we have an ability if purchasing whmcs to add customers who are already set up on the server(s) without causing an service interruptions? I think you understand what we are getting at - we want to use this as the new billing and management tool to make our operations more efficient, but do we have an ability to have it recognize or we manually add, the existing customers and then those customers log in and add their billing info? And while that is all occurring, there be no interruptions in their actual hosting simply because the billing info is not yet present. We obviously do not want to have to scrub the hosting accounts and then have the customer log in to set them up. Please advise. Thanks