The current system for registering vehicles in Argentina consists of an alphanumerical combination of three letters followed by three numbers. However, there have been two distinct phases in the registration of vehicles in the country, the decentralised phase, which ran until 1972, and the centralised phase from 1972 onwards.

Decentralisation commenced with the issuing of registration plates in the early 1900s. At that time the responsibility for assigning registration marks was devolved to each individual municipality or province. There are few records still in existence of the earliest registration marks, but from 1916 onwards each plate tells a story, as every district was responsible for designing their own plates.

In 1972 the Argentine government took the decision to standardise the format and design of the country’s registration plates. This new layout consisted of a prefix letter followed by six numbers and the registration number was printed in white against a black background. The numbers were issued in sequence, while the prefix letter acted as a province identifier. When Buenos Aires and Buenos Aires City exceeded a million plates each, they had to halve the height of the prefix letter to insert an additional digit beneath it.

From 1995, the registration plates have again been redesigned and standardised. The new regulations apply to all cars, including used cars, sold on or following 1st January 1995. The revised format does away with the provincial indicator and consists solely of three letters followed by three numbers. The process of standardising plates on vehicles sold prior to this date started with the letter R, whereas the new vehicles started from AAA 000.