Micropayment systems allow payments of low value. Low cost for transaction is the main requirement for micropayments. For this reason, anonymity, a desired feature, is difficult to implement in micropayment systems. This paper presents an anonymous and untraceable micropayment system that offers low transactional costs while the use of secure protocols avoids financial risks. The efficient anonymity is achieved thanks to the use of a double spending prevention technique. Finally, the bank behavior can be verified.