Hello Mark,
You are correct in there is no federal laws against going cashless and as of 2020 (there may be updates since) the following states and cities are the only ones I know of that outlaw cashless only pay options - NJ, MA, RI and San Francisco, Philadelphia, and NYC.
As you mentioned there are a number of audiences that are key to goals for community outreach for many museums (young, older, poor, immigrant) that line up with the stats of the unbanked or underbanked populations.
As someone who lives in NJ I have found that the work around for places like Six Flags who want to go cashless but avoiding being in violation of law and having a solution for all, is using a cash to card kiosk where the guest can get a temporary card that they place money on it. This reduces the cash handling to only an ATM style kiosk.
Good luck.
-Jared
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Jared Crellin
Account Director
ListenUp Audio
Atlanta GA
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