Andorra is a co-principality that had been jointly administered by France and the Spanish bishop of Urgell since 1278. In 1993, Andorra became a constitutional coprincipality, governed by its own parliament. It is the sixth smallest country in Europe with an area of just 181 square miles (468 square kilometers). The capital city of Andorra la Vella is the highest in Europe, sitting at an elevation of 3,356 feet (1,023 meters) above sea level. Stamps are issued by both France and Spain for use in the principality with Correos of Spain and La Poste of France operating side by side. The Spanish post boxes are red and French ones are yellow. However the postal code system, introduced in July 2004, has a different format from those of either Spain or France, consisting of the letters “AD”, followed by three digits.
The first postal route serving Andorra seems to have been established in 1837 with couriers conveying mail between Urgell and Aix during the Carlist War in northern Spain. Due to the difficulties in direct communication between Andorra and France, the mountain passes being frequently snowbound in the months from autumn until late spring, the Andorrans always depended on Seu d’Urgell to conduct the bulk of their business, postal or otherwise and that city was their principal point of communication with the outside world, including with their northern neighbor. At the Universal Postal Union Congress held in Paris in 1878, it was declared that Andorra was a subordinate of the Spanish postal service although it would be another fifty years before that postal service was actually organized. France ignored the UPU stipulation and established a rudimentary postal service between Porté and Andorra la Vella in 1887, consisting of two postmen travelling by foot. A French courier service inaugurated in 1892 continued to operate, virtually unaltered until 1931 when the present postal service came into being.
A Ministerial Decree dated 31st October 1927, created the Spanish Postal Administration of Andorra la Vella, empowering it to take all steps necessary to introduce a full postal service in the country. On 1st January 1928 post offices were opened throughout the principality and the postal service was officially inaugurated. At its inauguration, the Spanish Postal Administration consisted of the Head Post Office at Andorra la Vella and six sub-post offices at Canillo, Encamp, Les Escaldes, Sant Julia de Loria, La Massana, and Ordino. Seven postmen – all Andorran residents – were hired to carry on the service within the country, while the Head Postmaster – Don Filemon Lopez y Lopez – was a Spanish postal employee. The Spanish Administration commenced with the usage of the then current series of Spain – the 1922-1930 issue portraying the portrait of King Alfonso XIII. Overprints of this same set of stamps, plus the 1 centimo value of 1920 and the 20c express stamp of 1925, were released on 28 March 1928 with the unoverprinted values remaining valid.
The 2009 edition of the Scott catalogue for the Spanish Administration of Andorra lists 330 general issue stamps, four air mail and five special delivery stamps. It should be noted that the majority of the Spanish Andorra stamps issued until about 1950 are poorly centered and that well-centered examples will sell for approximately twice the value listed in the catalogue. Scott #102b comes from a souvenir sheet of four released on March 31, 1978, to mark the 50th anniversary of the Spanish postal service in Andorra. Perforated 13×13½ and printed in photogravure, the 10 peseta stamp portrays mail delivery in Andorra.