We use Freemius.com service as our payment processing provider and license management system. All our customers has access to Freemius User's Dashboard where they can manage the data related to their orders.
Customer has access to their personal and billing information through Freemius User's Dashboard and is responsible to keep it up to date. For instance, customer is able to cancel renewals for their annual license if their wants to.
It is possible to transfer ownership of the account to another person. There is a special functionality for this. It is also possible to simply change the email address and give away another person yoru account. However, be aware of the fact that simply changing the email does not change/update billing/payment information in any matter. Customer has a full responsibility of proper transfering of the ownership of their accout to a third-person and all the consequences of leaving the old personal/billing/payment data inside their account.
These are two advanced, but quite common use-cases:
Developer & Billing Department: Larger organizations usually have a billing department which is responsible for swiping the credit card, rather than the developer who actually installs the product and sets it up.
Freelancers/Agency & Client: In many cases when working with agencies, the agency is responsible for maintaining the website, its plugins and themes, while delegating the payment for the premium plugins/themes to its client.
To address those use-cases, Freemius introduced a new Payer persona, in addition to the Customer persona that it already had. So for example, when an agency needs its client to actually pay for the paid product, they can simply choose to send the upgrade link to the client:
The Payer persona is restricted to control all the billing aspects, while keeping the ownership of the license and access to support for the agency. Moreover, all the billing related emails will be emailed to the Payer, while the technical emails, like how to install the paid product and its license key, will go directly to the agency (the Customer persona).