Clarification on upgrading to customer account

To upgrade my PTC account to Customer account I will need a Customer number.

The thing is I use PTC Creo Parametric on my office system. Its a floating license so other people will also be using the license.

My question is, how many people can have a customer account using the Customer number?

Is it one account per Customer number or is it like users of the customer company working on floating licenses can all have customer accounts?

Thanks and regards,

Suraj