How can Ford justify increasing tax on my new car by £300 if the WLTP hasn't been introduced yet?

The Worldwide Harmonised Light Vehicle Test Procedure (WLTP) is being introduced for all new cars registered from 1 September 2018 and the new car I had ordered from Ford in May 2018 will not be delivered until July 2018. Yet, Ford has increased the tax band in anticipation and added it to my bill (£205 to £515). How can they justify the increase if the tests aren't introduced until September 2018?

Asked on 5 June 2018 by Mr fallon

Answered by Honest John
If the car is now certificated to £515 for first year tax, that means that its CO2 has risen from the 131-150g/km CO2 band to the 151-170g/km CO2 band under the new test regime. Once the car is certificated, that's it, even if the actual increase that jumps the car into the next band may only be a few g/km.
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