Benefit-in-kind (or BIK) is a tax on employees who receive benefits on top of their salary. For example, if you have a company car for private use, you will have to pay a BIK contribution or company car tax.
Every car has a BIK percentage banding, based on CO2 emissions, and a P11D value, which is the list price, including extras and VAT.
BIK for electric cars is 0% in the first year, 1% in the second, 2% in the third and 3 in the fourth year. Much lower than fuel cars which typically see 20% or 40% depending on your tax band.