Company cars: baseline CO2 emissions 2018

Author: Peggy Criel

If a company car is made available to workers or company managers, a taxable benefit of all kind originates when the car may be used for private purposes. One of the factors to calculate the taxable benefit for the income year 2018 correctly is now known, namely the baseline CO2 emission.

Lump sum estimate of the benefit

Since 1 January 2012 the benefit of all kind generated by the provision of a company car to a worker or a company manager is calculated as follows:

(List price x degressive coefficient) x 6/7 x CO2 percentage

Baseline CO2 emission determines the CO2 percentage

In order to determine the CO2 percentage, the CO2 emission of the car is compared to the baseline CO2 emission. In 2017 the baseline CO2 emissions amount to:

  • 105 g/km for cars with petrol, LPG or natural gas engines;
  • 87 g/km for cars with diesel engines.

The base CO2 percentage is 5.5% for the baseline CO2 emissions given above. When the emission of the concerned vehicle is higher/lower than the baseline CO2 emission, the base percentage is increased/decreased by 0.1% per gram CO2. The CO2 percentage must be at least 4%. The maximum CO2 percentage is 18%.

Each year the baseline CO2 emissions are laid down by Royal Decree.

Baseline CO2 emissions 2018

The baseline CO2 emissions for income year 2018 are:

  • for cars with petrol, LPG or natural gas engines105 g/km. The baseline CO2 emission for these vehicles does not change;
  • for diesel cars86 g/km. This is a decrease of 1 g/km compared to income year 2017.


The worker disposes of a company car with a diesel engine that he may use for private purposes. The CO2 emission of the car is 90 g/km.

The baseline CO2 emission for company cars with diesel engines is 86 g/km for 2018. The CO2 percentage for 2018 is 5.9 % (= 5.5 % + [(90 – 86) x 0.1 ]%). In 2017 the CO2 percentage is 5.8 % (= 5.5 % + [(90 – -87) x 0.1] %).

Source: Royal Decree of 13 December 2017 amending the Royal Decree for the implementation of the 'Code des impôts sur les revenus 1992' with regard to the section of the benefits in kind in the event of free private use of a company car, Moniteur belge, 19 December 2017.