Clients should be able to upgrade and downgrade their services between other packages in the same package group which use the same module.

The module should be notified when changing the package, so that it may perform an API call if desired. For example, changing a cPanel hosting plan in WHM to affect resource changes.

This feature should be implemented similarly to CORE-1093 by adding an additional drop down under the "Status" button in the client area when managing a service called "Upgrade / Downgrade". Selecting this option will open a modal box where the user may select a different package. All other packages and their pricing options should appear. If there are no other packages in the same group with the same module, do not display the "Upgrade / Downgrade" option in the status dropdown.

Extraneous:

When selecting the new option, the operation should take place immediately, however the action should be prorated per any company/client group settings. An invoice may be generated (due today) if upgrading and a prorated amount is due. In this case, direct the user after performing the upgrade to the invoice pay form. If the user is performing a downgrade, issue a prorated credit to their account as an "In House Credit" for the difference, per any company/client group settings/rules.

Consider an additional upgrade email notice, either to staff or to clients where staff can BCC subscribe.