Writing Down Allowances and your Fleet vehicles

When you buy business assets, you can usually deduct the full cost, up to a certain limit, from your profits before tax using annual investment allowance (AIA) to reduce your company’s corporation tax liability. However, company cars don’t qualify for AIA, therefore, fleet managers need to use writing down allowances instead.

A Writing Down Allowance allows you to deduct a certain percentage of the cost of an item from your profits each year. The percentage you deduct depends on the item. For business cars, the rate depends on their CO2 emissions to encourage the use of low emission fleet cars.

Due to inflation, the more quickly the cost of a company car is offset the more your business will benefit. Rates are reviewed annually.

For company cars registered new from 2021/22 tax year they are:

CO2 emissions

Writing Down Allowance (per annum)


100% First Year Allowance

1 to 50g/km


Above 50g/km