[dunham]

I've got a local cafe that pre-selects a $3 tip on a $5 purchase.

[Graziano_M]

I try to 'punish' for these and tip less than I would normally.

[koolba]

At an airport once the coffee stand had a girl behind the counter that would just hand you an empty disposable cup. She didn’t even handle cash, it was card only using a self checkout POS system. And it still asked for a tip with the default of 20%.

There should be a way to specify a negative tip.

[mmooss]

The server isn't the one who configured the UI, and probably needs the money. You're punishing the wrong person.