This would never fly in Switzerland. You need to accept Swiss Franc Banknotes of any denomination as settlement for any monetary debt (this includes a purchase of a 1.- stick of gum paid for with a CHF 1000 Bill. there will be some arguing required for that one in practice, but the law is clear).

Wrong.

The relevant law (art. 3 WZG[0]) requires persons to accept all banknotes (and up to 100 coins per transaction) as payment, but this only applies after a contract has been formed. It's perfectly legal for any store to indicate to customers that it will not accept large-denomination notes or cards[1]. If the customer is not willing or capable to pay using the accepted means of payment, no contract is formed, and the chewing gum remains with the store.

[0] https://www.admin.ch/opc/de/classified-compilation/19994336/...

[1] https://www.srf.ch/sendungen/kassensturz-espresso/geschaefte...

You say that, Espresso is a good source for this kind of thing and I'm not saying your wrong. But the letter of the law does state that everyone has to accept Swiss banknotes with no restrictions.

My personal legal asessment: If you were to form a contravt for purchase of goods and stipulated ahead of time that payment will be made in small bills (or electronic payments only), receiving payment with 1000.- bills would give the right to demand compensation related to handling large bills (security, verification etc.) due to the contractual breach, but it would not allow you to deny the money and demand payment as contracted.

As I understand in the US a purchase is not the same thing as a debt, i.e. nobody has to accept any particular type of currency for a purchase, only for a debt. Is Switzerland really different here?

Is that even allowed? I don't know the specific law here, but in my country (France) a shop can not legally refuse to be paid in the legal currency (in cash). It can refuse credit card or checks, though.

How I wish it was this way in Sweden. Unfortunately it's not - there is no requirement to accept any specific kind of payment and it's by now rare to see anyone pay with cash.

This is the first time I've heard of something like this. I grew up in Greece during the mass deflation of the currency and people wouldn't accept anything but cash. Interesting to learn that it works both ways.