After William T. Riker broke the bank at Quark's Bar by winning more latinum at the dabo table than Quark could pay, Quark offered Riker vouchers that were only redeemable at the bar. Quark apparently set up a house account for Riker, and debited the vouchers after Riker offered them back to Quark in exchange for information about Lursa and B'Etor. (TNG: "Firstborn")
It is unclear whether the type of voucher referred to in "Mudd's Passion" exists at all, or if the entire concept of their existence was faked. In the novelization of that episode (as published in Star Trek Log 3), these are referred to as "credit vouchers" and Mudd claims that he apparently gave the miners an Andalusian pleasure slave in exchange for the fabricated vouchers, although the miners were annoyed to discover it was actually a pneumatic automaton.