At HostStage, you are given several options for your payment such as setting a subscription for your services or a PayPal billing agreement.
You may also add funds at any time which will be automatically used to clear your invoices as they are generated. The only requirements to add funds is to have an active order / service.
To proceed with adding funds to your account, you would simply need to login to your HS Manager and click on Add Funds or the link below:
You'll be then prompted to select an amount and a Payment gateway as shown in the screenshot below.
Upon clearing the invoice, the funds will be added automatically to your account and you'll be able to check them from your account balance from your HS Manager.