Go through the process menu Energy > Settings
Select Tariff Library
In the view that opens, click Add Energy Supplier
A pop-up window opens where you can enter the Supplier name and consumption item.
Then press Save. The added Supplier will appear as its own line in the Tariff view.
To edit Supplier-related information, click the three dot icon, and then click Edit
To edit price information, select Cost Information through the three dot icon.
The information is broken down into different tabs.
To add new information, click Add
Price information can be defined for the time interval and can be changed when prices change. (the price takes effect in the minute before the start date, i.e. set the start date 31.3.2018 23:59 if you want the prices to take effect on 1 April 2018) 
Click Close when the information is filled in.
To assign the metrics to the correct item/invoice attachment, price information must be further defined per meter.
Start by going from the process menu Energy > Meter management
Select a meter and open it in an expanded view. By cost information you select Edit, to open a window to set up a sales tariff.
Finally, press Save
To assign invoices to the correct cost center, you must create a cost center. Go through the process menu Invoicing > Settings
In Settings view, click Cost Center Management, and then click Add New Cost Center
Through the window that opens, it is possible to fill in the basic information and energy invoicing information of the cost center.
In Invoicing of energy (*) tab, you define the meters to be invoiced from the cost center.
Click Add to Cost Center Meter to add the meter to be invoiced.
In the window that opens, you specify an item, and you select the metrics to be invoiced from the list that is updated according to the property selection.
The meters to be invoiced are selected by ticking the check box to the left. The view also modifies the proportion of metrics that you want to invoice.
(this way, for example, the consumption of the meter can be divided between several tenants on the invoice)
Finally, press Save