> I used to think "I should be nice to merchants" and pay everything in cash.

That is only "nicer" as it allows to evade taxes. (Which some may consider nice)

But cost for cash is comparable to card payment if looked at seriously

* You need working time to count it

* You need working time to bring to bank (or request pickup, which costs)

* The bank will charge the deposit

* The bank will charge for the change you need

* In the shop the cash has to be protected (safe? Protection against robbery)

* This requires procedures for shift change etc (thus training time and prolonging working time)

* There is a risk of fraud (counterfeit, swap tricks etc.)

* Employees might have sticky fingers

I own a business that does about $10-$15k mo USD in cash and card transactions and only some of this is true.

I bought a cheap cash and coin counter for about $400 on Amazon, which means it takes me about 2m to count whenever I need to balance the register.

For reference, with my POS I pay about $400 per MONTH in cars fees (square).

It does take time to bring it to the bank, maybe 5-10m a week for me.

My bank does not charge for deposits or change; this would be insane and I've never encountered this in the US.

Counterfeits aren't generally an issue for small bills in practice; for $20+ we use a 50c testing pen that takes about 2s per transaction.

Sticky fingers are easily caught by balancing the register after each shift which is again about a 2m operation with cash and coin counters.

Unless you're handling huge amounts of cash, cards are WAY more expensive to deal with IMO, especially because the fees scale as a percentage of revenue, so you can't just increase sales and lower your margins.