It has been estimated that for every 1 million American notes in circulation, 500 is counterfeit. In 1993 USA authorities seized some US$140 million in counterfeit bills, considered to be only a fraction of those in existence. Very high quality counterfeit bills cost the Federal Reserve of USA several million dollars in 1993 when for several months it was obliged to suspend the policy of charging back to all member banks the cost of counterfeits it had detected.