I send six postcards back to the USA every time I go someplace. So I always have to figure out the local postal situation when I go someplace new. Well Andorra was a bit unusual because there is no Andorran post office.
Since Andorra has joint heads of state the country also has two postal systems. La Poste is the French post office and Correos is the Spanish post office. Each postal authority issues its own Andorran stamps for international mail.
You first have to decide if you want your mail processed in France or Spain. Once you decide, you need to go to the appropriate office and purchase Andorran stamps. When you drop your mail in to a post box you have to be sure to use the correct one. Spain won't process letters with French Andorran stamps and France won't process letters with Spanish Andorran stamps.
Once the mail is collected it is sent off to either France or Spain for processing. I bought stamps at La Poste so my postcards will all arrive with French postmarks.
Until 2009, domestic mail within Andorra was free so no stamp was needed. Now locals have to purchase either French or Spanish stamps too.
Since Andorra has joint heads of state the country also has two postal systems. La Poste is the French post office and Correos is the Spanish post office. Each postal authority issues its own Andorran stamps for international mail.

Once the mail is collected it is sent off to either France or Spain for processing. I bought stamps at La Poste so my postcards will all arrive with French postmarks.
Until 2009, domestic mail within Andorra was free so no stamp was needed. Now locals have to purchase either French or Spanish stamps too.