Vehicle registration plates of Estonia are divided into 18 categories, the most common of these (A1) is composed of three numbers and three letters (e.g. 123 ABC). Most registration plate types have black letters on a white background, and the plates are the same size and length as other European plates (520 × 113 mm). Previously the first of the three letters indicated the region of Estonia in which the car was registered; however, as of 2013, this is no longer the case. The third digit from the numbers indicated states when the car is due an inspection. It can be inspected up to 2 months after that digit. The registration plates are printed on an aluminium sheet with minimum thickness of 1 mm and must fulfil the requirements of ISO 7591:1982. All plates are issued with the blue European Union identification label, except types A9 and B2.