> 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.

Unless, of course, physical cash no longer exists, and all you have is some sort of ephemeral digital cash in a financial institution that can be easily subject to a negative interest rate policy. A bank balance can lose nominal value with NIRP, but cash in-hand can't. Hence, the War on Cash.

Physical cash CAN lose value. Very fast too.

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.

Nominal value was the important term in the parent, i.e. a 100 dollar bill can't become a 99 dollar bill.

Sure, but nominal value is not what you use to buy things. The nominal value in my bank account won't just go down on its own either. But what I can do with it will.

Or is there a mechanism I don't know about that can lower nominal numbers in untouched bank accounts?

> The nominal value in my bank account won't just go down on its own either.

It would with negative interest rates.

presumably to reduce the inflation of prices. 6 of one, right?

The number on the paper != purchasing power

Sure it can, banks would just have to modify the exchange rate between physical cash and bank deposits.

Meanwhile in my bag I have a crisp $100 trillion Zimbabwe dollar bill I use as a bookmark.

> A bank balance can lose nominal value with NIRP, but cash in-hand can't.

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.

Where do you see this? I see authoritative statements saying otherwise. "Private businesses are free to develop their own policies on whether or not to accept cash unless there is a State law which says otherwise" https://www.treasury.gov/resource-center/faqs/Currency/Pages...

> For example, a bus line may prohibit payment of fares in pennies or dollar bills. In addition, movie theaters, convenience stores and gas stations may refuse to accept large denomination currency (usually notes above $20) as a matter of policy.

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).

OP is referring to some source of authority but not actually naming it. If OP is referring to the message on the Treasury notes, OP's interpretation is reasonable but OP should read more texts.

OP qualified it with "Once services have been rendered", so OP's interpretation is exactly correct in that context.

You can't compel someone to pay you something other than cash. For people who insist on paying in cash, a business can just refuse to serve them.

This assumes the service has already been rendered. If I own a store and you want to buy a candy bar from me, I can end the transaction when you attempt to pay me with a $100 bill. Since I haven't actually given you ownership of the candybar, there is no debt in place, yet. A restaurant doesn't have the same freedom, since they generally accept payment after the service is completed and you already owe them the debt for the meal.

>A restaurant doesn't have the same freedom, since they generally accept payment after the service is completed and you already owe them the debt for the meal.

They can however place signs visible in their store or write it on their menu that they don't accept $100 bills.

They can add signs saying the sky is green, they still need to accept cash as long they are collecting a debt.*

*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.

But when ordering something, you are entering a contract. By placing a sign saying "We don't accept cash" they are placing a condition under which they'll enter a contract with you.

By ordering, you are implicitly agreeing to that condition.

The tricky question is - how does this work at petrol stations? You already have the fuel in your tank when you go to pay. Surely the service has been rendered at that point?

You pay in advance if you want to pay cash. Or, you give the pump your credit/debit card (which is also paying in advance).

In fairness, it hasn't always been like that everywhere. In my hometown, the move to 'prepay when using cash' only happened about 10 years ago. I distinctly remember working at a gas station in high school and dealing with older customer who refused to believe that they couldn't just pump then pay.

Agreed, and I'll go one further saying that it's still not 100% this way everywhere. I'm from a pretty rural area and at several of the stations there you're still free to pump then pay in cash.

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?

Yes, if you overpay then you go back in and get the change back. If I give the cashier a twenty, but only pump $10 worth, then I get $10 back from them. Most people are pretty good at estimating it though, so generally the people that pay in cash will just leave the few dozen cents they didn't use.

This is the first time I'm hearing about petrol stations where you pay cash in advance and I live in EU. Just fill up the tank and pay at the till?

No, pay at the till, then fill up the tank. This is in the US.

They usually have signs at the pump saying "No $100" notes.

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 don't pay cash often, but when I have, I've pre-paid inside the store, and the pump automatically stops when I've gotten the correct amount of gas. It may be regional. This shows people posting a mix of pre- and post-pay anecdotes: http://www.democraticunderground.com/discuss/duboard.php?az=...

The average American commits 3 felonies a day. Just add it to the list.

http://www.amazon.com/Three-Felonies-Day-Target-Innocent/dp/...

Tell that to every government agency.