Vehicle registration plates of Portugal

The Portuguese vehicle registration plate system for automobiles and motorcycles is simple and sequential. The system has no link to geographical locations or similar. It is an incremental numbering system consisting of three groups of two characters, separated by dashes. This system started in 1937 with AA-10-00, which ran out on 29 February 1992. This then went on to 00-01-AA and changed to 00-AA-01 in 2005. This last sequence was exhausted early in 2020, and it was announced on 3 March that it had been replaced by the sequence AA-00-AA. (The first registration issued was actually AA-01-AA, the 00 having been reserved.) Moreover, the letters W and Y, never before used, and the letter K, used only for a short-lived series for imported vehicles in 1997 (see below), are being employed in the new system, meaning that this sequence should last more than six-and-a-half times as long as the previous. At current rates that it would not need replacing at least until the end of the 21st century, but the expected lifetime of the series is stated as being forty-five years.
In 2020 with the change to the AA-01-AA, the yellow ribbon containing the date of first registration is being discontinued due to authorities in other countries mistaking the registration date as an expiration date. In addition, the dashes that separate each block of numbers or letters have been removed from the new plate format. Owners of vehicles that need replacement plates will be able to choose whether such plates are produced according to either the old or new format.
Colours.
Initially there were white characters on a black background. In 1992, the design was changed to one of black characters on a white background in metal or fibreglass; in that same year, the European blue ribbon was added with the Portuguese 'P' denominator. In 1998, a yellow ribbon on the right side was added with the month and year in which the car was first registered (e.g. 99/12 for December 1999 - the year comes on top of the month). This was different from systems such as in Germany (where the numbers indicate the start and end month of the vehicle's registration) and more similar to systems such as in Italy (where the date indicates the year of vehicle registration). Note that the date is that of first-ever registration of the vehicle, not the date the vehicle was registered in Portugal. Some vehicles carry plates that have a year and month seemingly out of tune with the alphanumeric sequence, and the reason for this is that these are imported used vehicles. The yellow ribbon has been discontinued with the introduction of the new format in 2020.
District codes.
Trailers and vehicles for export have the following district code letters in their licence plates:
Until the 1970s only the codes A, AN, C, H, L, M and P were used. After that, other registration offices were created with new codes.
The following special codes are also used for trailers: 
History.
1901-1911.
Local licence plates were issued from 1901 onwards by the District Governor’s Office, and usually consisted of the full name or the abbreviation for the district followed by a serial number. (e.g. "LISBOA 123" or "L.XA 123" for a vehicle registered in Lisbon).
1911-1936.
A national car registration system was established in 1911. The country was divided into zones (North, Centre, South, and, from 1918, the Azores and Madeira), each having an identification number sequence for the licence plates, which was N-000, C-000, S-000, A-000 and M-000 respectively. Hire cars had a letter A added after the registration (e.g. S-4226-A) and provisionally registered vehicles had WW added (e.g. S-1703-WW). The plates were white letters on a black background.
By the mid-1930s so many vehicles had already been registered, especially in the South Zone (which included the city of Lisbon), that the identification number had already reached five digits. As this created difficulties in the identification of vehicles by authorities, the system was changed. However, in the Azores and Madeira it persisted until 1962.
1937-1992.
On 1 January 1937, the second national car registration system came into force. This consisted of the sequence AA-10-00 to ZZ-99-99. The sequencing by zones was maintained, with the letters AA to LZ reserved for the South (Lisbon), MA to TZ for the North (Oporto) and UA to ZZ for the Center (Coimbra). Again, the plates were white letters on a black background.
Vehicles registered under the previous system had to change to the new one. In Lisbon the vehicles of series S-000 and S-1000 changed to series AA-00-00, those of S-10000 to AB-00-00, those of S-20000 to AC-00-00 and those of S-30000 to AD-00-00. In Oporto the changes were from N-000 and N-1000 to MM-00-00 and from N-10000 to MN-00-00. In Coimbra all vehicles changed to the series UU-00-00. In doing so, re-registered vehicles kept the last four digits that they had had under the old system so that e.g. C-123 changed to UU-01-23, N-1234 to MM-12-34 and S-12345 to AB-23-45.
The letters MG, and later, ME and MX were reserved for the Army, AP for the Navy, AM for the Air Force and EP for government ministries. The letters CD, CC and FM were reserved for diplomatic vehicles (respectively for diplomatic, consular and non-diplomatic personnel), but with red characters on a white background. The letters TA, TB and TC, in red plates with white characters were reserved for temporary licences respectively in Lisbon, Oporto and Coimbra. National Republican Guard and the former Fiscal Guard had special sequences beginning respectively with the letters GNR and GF.
In the Azores and Madeira the new system was only adopted in 1962. The Azores were divided into three registration districts: Ponta Delgada, Angra do Heroísmo and Horta. The letters AN were reserved for Angra, AR and AS for Ponta Delgada and HO for Horta. For Madeira the groups MA and MD were reserved. The white letters on red TD, TG, TH and TF were for temporary licences respectively in Ponta Delgada, Angra, Horta and Madeira.
In the 1970s, new district registration offices were opened, and letters reserved for them: EM and EV for Évora, ZA and ZB for Braga, ZC and ZD for Vila Real, ZE and ZF for Aveiro, ZG and ZH for Guarda, ZI and ZL for Santarém, ZM and ZN for Setúbal and ZO and ZP for Faro. As Évora was considered a central office it also had a temporary licence code: TE. However, as the zonal registration system was abandoned relatively soon afterwards, most of these sequences were not used as zonal identifiers.
In the early 1980s the reservation of letter sequences by zone was discontinued, and vehicles were registered sequentially at a national level, so that letter combinations previously reserved for Oporto and Coimbra might be seen on vehicles registered in the Lisbon offices of the National Registration Office.
In 1985, diplomatic plates adopted the format 000-CD000, 000-CC000 or 000-FM000, with the first three numbers a country identifier, and the last three sequential.
1992-present.
In March 1992, the AA-00-00 format came to an end and was succeeded by the genuinely national-level 00-00-AA sequence. The type of plate also changed to black characters on a reflective white background, with the blue ribbon, with the emblem of the European Communities (now Union) on the left hand side and the letter P as a country identifier. Under this new sequence no combination of letters was reserved for specific entities or areas. However, in 1997 the combinations KA to KZ, the first letter of which sequence does not occur in the Portuguese alphabet and so had not previously been used, were given over to preregistered imported vehicles. The groups WA to WZ and YA to YZ were likewise reserved for this purpose, but the system was abandoned at the end of the year.
In 1998 a yellow ribbon with the date of the first registration of the vehicle was introduced, placed on the right hand side of the plate. This was mandatory for all newly registered vehicles, whether new or second-hand imports. In 2005 the 00-00-AA sequence ended, and 00-AA-00 was introduced. The last of the old sequence was 99-ZZ-99 and the new sequence started with AA-01-AA. A comprehensive list of the history of sequences from 1956 to mid-2015, in Portuguese, can be found here.
Sequences with the letters CU, FD and OO, were originally not used, the first two because they coincided with taboo slang words (CU - "arse", FD - Portuguese abbreviation for "fuck") and the last to avoid confusion with 00 (zero, zero). However, The CU sequence was used in 1982 on Lisbon registered vehicles and OO in 1966, 1967, 1978, 1979 and 1982 on Oporto registered vehicles.
It is technically incorrect to say that licence plates are issued. The authorities issue a registration number and it is then the owner's responsibility to have the plates made up, either of plastic or metal, on production of the appropriate documentation. In the case of new car sales, this is done by the dealer.
Portuguese Overseas Territories former plates.
The models of Portuguese car plates were followed by the then Portuguese overseas territories. At the beginning the model of 1911 was followed. Each colony had a group of one to three letters which designated the colony itself or a district inside the colony. The letters were followed by a serial number (e.g. G-1234 for a car registered in Guinea or CVS-1235 for one registered in the south-east district of Cape Verde). 
In the 1950s and 1960s, the licensing systems in all colonies were changed to systems based on the Portuguese one of 1937. By territory the sequences used were:
With some minor differences, these systems are still in use in São Tomé and Príncipe, Macau, and Angola. Cape Verde has adapted the system to use different two-letter codes for each island.