"This note is legal tender for all debts, public and private"
Once services have been rendered, it's illegal for someone to not accept cash as payment.
Once services have been rendered, it's illegal for someone to not accept cash as payment.
That's actually incorrect. "Legal tender" has a much more subtle effect; what it means is that an attempt to pay in cash meeting the other legal requirements for a tender of payment has an effect on whether and how much damages may be collected if the creditor later sues the debtor for the debt.
That doesn't mean that it is illegal not to accept cash, it does mean that not accepting cash for a debt already incurred may, under certain circumstances, negatively impact the availability of legal recourse to collect the debt.
My parents lived through the hyperinflation in Yugoslavia in the 90's. The stories they tell are ... fun. Ideally you exchanged everything into deutsche marks as soon as you got it.
New denominations were being printed every few weeks because the currency was losing value etc.
Hell, even when we became Slovenia I remember that at first, the highest bill was 1,000. Just ten years later, the highest had to be 10,000 because the thousand one just wasn't cutting it anymore. It was too impractical for the prices.
For a more drastic example: in pre-war Germany it was more common to get mugged for bread than for cash. Wads of cash just weren't worth enough to bother.
Or is there a mechanism I don't know about that can lower nominal numbers in untouched bank accounts?
It would with negative interest rates.
If by "nominal value" you mean "printed face value", then perhaps not (though there are plenty of time or environment-sensitive printing technologies that would allow that to change, even if there might be all kinds of good arguments against using them on currency.)
If, instead, by "nominal value" you mean "official exchange/redemption value in the units of account in which the cash is denominated", sure it can; in fact, cash that does that has been suggested and, IIRC, used in some cases -- this is done by making the nominal value (that is, the official value in current units of account) equal to the face value at the time of issue, but decreasing over time based on the duration between the issue date on the cash and the current date, so that cash held longer is worth less, even in nominal terms, as a tool to increase the velocity of money.
These are all examples where payment is being offered before service is rendered. OP is referring to instances where payment is being collected for services already rendered (i.e. debts).
Edit: At least in Europe you usually pump before paying by card/cash in the store. I guess it differs from the US because of the high crime rate there.
I actually didn't realize pay-first for cash transactions had become the standard until recently as I made the swap shortly after 'pay at the pump' became common and never really looked back. How does it work? You just estimate how much you need, and the pump cuts off at that point? If you can't hold that much you go back for a refund?
They can however place signs visible in their store or write it on their menu that they don't accept $100 bills.
*Fastfood / food trucks are different as you pay before reviving the food.
PS: Though they can ban you from coming back after this. And the payment needs to be reasonable. 10$ for a 9.50$ meal is reasonable a 100$ bill is not.
By ordering, you are implicitly agreeing to that condition.
http://www.amazon.com/Three-Felonies-Day-Target-Innocent/dp/...