That's not a concern of anyone. Cell towers will still work and 96% of US population have cell phones. And power is never down so long that all of society can't function. Usually a day or two at the most. Companies would also give additional days to make payments, from such unforseen circumstances. From a business standpoint, a cashless society removes a huge amount of headache. No more worrying about register drawers not being balanced at the end of the day. No worry of employee stealing cash. Nearly impossible to mess up a transaction. All accounting is handled instantly, and recorded in ledger. Instant analytics and analysis down to the minute. No worry of getting held up for cash once robbers know there is no cash in the store to be had. So many pluses.