Some expats feared the worse when the Banco Nacional Web site went out of service Tuesday morning.
The problem was more technical than financial. The bank reported that a central system of communications failed.
By 2 p.m. the bank was back in business, although the detailed technical nature of the failure was not reported.
As a result of the failure, tellers could not post deposits and payments and online users could not make transfers. The bank said that the administration authorized bank branches that had customers waiting to remain open until 4:45 p.m. The branches usually close an hour earlier.
When the incident happened, the bank was quick to send out notices to the new media and also made use of a Twitter account.
Banco Nacional is a major state bank with deposits guaranteed by the Costa Rican government.