The cop-out snide answer is “anybody who lives outside the US and doesn’t use dollars as their main currency”. The answer that actually addresses the central q

The cop-out snide answer is “anybody who lives outside the US and doesn’t use dollars as their main currency”. The answer that actually addresses the central question, however, would follow the lines of “if a scrip does not have institutions that use it natively across the board to address all functions of a currency, but rather depends on gateway institutions, then it isn’t a currency”. (A ‘scrip’ is a kind of quasi-money token system such as “Disney Dollars” at Disney’s amusement parks, vouchers used in company towns, and so forth.)