Pro tip: I stacked a $4 store coupon on a $3 clearance item and the register paid me 11 cents
Last Tuesday I was at the grocery store on 5th and grabbed a box of pasta marked down to $3 because the box was dented. I had a $4 off coupon from the store app that was about to expire that same day. The cashier scanned both and the total went negative, so she handed me a dime and a penny back. I stood there for a second because I thought she made a mistake. She laughed and said the store policy allows it when a coupon beats the price. I learned to always check the clearance shelf right when a good coupon is about to die, since that combo is where the real wins hide. Anyone else ever walked out with change in your pocket from a deal like that?
Are you sure she actually handed you change back, or did she just round it down and let you go? I mean, most stores I've been to will let the coupon take the total to zero, but they won't hand you actual money back. That would be them paying you to shop there, and that opens up a whole weird thing with people just grabbing coupons and free stuff. Maybe it's just me but that sounds more like the cashier being nice and covering the 11 cents herself, which is cool of her either way. Still a good win, I just don't think it's a real store policy thing.
Change back on a coupon usually depends on whether the register treats the coupon as a payment or a price cut. Store coupons and e-coupons almost always just lower the price, so the register won't spit out cash if it hits zero, it stops at zero. If she handed you 11 cents from her own pocket that's a whole different thing and honestly way more interesting than the coupon itself.