Yes we have a lot of business centres doing exactly that. Simply select your standard tariff, edit to suit and then save this with a new name. You can have multiple tariffs saved and select which one you would like to apply to any tenant.
You can add your own codes at any time. Just go to the Tariff editor, press the Add code button, enter the Dial code properties and press save. If you are maintained, we'd suggest contacting us and allowing us to show you how to do this as it is covered under maintenance. For those who do not have maintenance, full instructions are available in the on-line manual.