Most businesses accept Visa, American Express and Master Card plus many other lesser known ones. Some of the larger retail establishments and banks issue their own for their customers. The four state banks and many of the privately owned ones have cajeros automáticos (automatic cashiers) in different locations in San José and the larger cities for the convenience of their clients. The Banco Nacional de Costa Rica, which is the largest bank between Mexico and Colombia, advertises that it's always close to you no matter where you are. I particularly like the Visa card from that bank because its interest rate is the lowest of all cards and there's no annual service charge. The use of debit cards are now very common and well-extended in the country.
Costa Rica has a reliable postal service, although at times delivery of correspondence is somewhat slow. It was modernized so it's much better than it was a few years ago. Now it also offers internet service to the public and has allied itself with a worldwide courier service for quick international deliveries. It will also allow you to use a Miami mailing address through it.
Correos de Costa Rica rents mail boxes in all of its many locations for a very reasonable cost ranging from $12 to $40 a year. And it doesn't charge per weight or volume received as do the private mail services. For Correos de Costa Rica all that is necessary is that the mailing pieces you receive fit in your box.
Despite the modernization which the postal service has undergone, many persons still prefer to subscribe to privately owned mail services. There are many available which will assign you a Miami mailing address and deliver to your home or office which is very convenient. Most of them charge a minimum which runs around $15 monthly plus the weight of your correspondence after the maximum has been reached.
During several years I was subscribed to such a private service and it was very dependable and fast. However, I later suspended it because magazines to which I was subscribed began selling my address to catalogue senders and other mail order companies. It came to a point where I was being flooded with unwanted mail. If you're not in a hurry to receive a package or magazine from the states, it's better to use the government post office. It will cost you much less. However, if you need correspondence in which timeliness is important, such as would be the case of an important newsletter on which to take a decision, then the private service is advised. Correos de Costa Rica is frequently offering new services to marketers, so it's good to keep posted if you plan to go into business. The main post office is located on Calle 2, Avenidas 1 / 3 in San José.