A tax (formally called vehicle excise duty) that must be paid in respect of any mechanically propelled vehicle used, parked, or kept on a public road. It is an offence to fail to pay it. Electrically propelled vehicles and invalid vehicles do not have to be taxed, and no tax is required when a motorist is driving to and from a prearranged MOT test. It is also an offence to fail to display a tax disc showing that the vehicle has been taxed, unless one has applied for a new disc before the old one expired and it is within 14 days from the date of expiry. The tax disc must be displayed on the nearside lower corner of the windscreen. Failure to pay road tax or display the tax disc is punishable by fine, but is not subject to endorsement.