You can use a separate electricity meter connected directly upstream of the wallbox that measures the charging process of the company car exclusively.
According to the BMF (Federal Ministry of Finance) guidance, the following are permitted:
Stationary electricity meters
Mobile electricity meters
Meters integrated into the wallbox
An MID-certified meter is not strictly required—based on our understanding, non-MID meters are also permissible.
Note: NAVIT is not a tax advisor. The final assessment regarding tax recognition lies with you or your company's tax advisors.