Web designers paying for a client's hosting, or a client paying an invoice raised to an agency, is common and causes confusion when it is not set up deliberately.
THE PRINCIPLE
Whoever holds the Client Area account is our customer. That is who we take instructions from, who we bill, and who we can discuss the account with. Who physically pressed the pay button does not change that.
IF YOU WANT A THIRD PARTY TO PAY
Send them the invoice PDF, which they can pay by transfer using the invoice number as the reference. The account and the service remain yours.
IF YOU MANAGE SITES FOR CLIENTS
Decide early which model you are using:
You hold the account and bill the client yourself. Simple, but you carry the payment risk and the client has no direct relationship with us. The client holds their own account and you are added as an authorised contact. Cleaner when the relationship ends. You use reseller hosting, which is designed for exactly this.
ADDING AN AUTHORISED CONTACT
Account > Contacts lets you add someone and choose which notifications they receive, including billing only. They can then be dealt with on the account without sharing your login.
Never share one login between an agency and a client. It causes disputes nobody can resolve later.