Self serving checkouts ask you how many bags you want and charge for them in the UK. I have seen a growth in adults using backpacks, it wasn't the norm before the bag charge.

I was in Maine recently and they charge for bags there. At Walmart, the self checkout staff member was also selling bags to the people who needed them, in addition to monitoring everything else that happens at self checkout.

The supermarket close to my home has self checkout, you just have to scan the bag in addition to your products.

In Canada we just fully banned plastic bags. Walmart just doesn't offer any bags at self checkout anymore besides the reusable ones. It's kind of annoying if you forget to bring bags but it's not a huge deal. If I'm walking I'll just fill my personal grocery cart, or if I'm driving I'll just throw everything loose in my car. If I do need a bag I'll just spend $0.25 on a reusable bag.

It's really not a big deal like a lot of people expected

I’m in a conservative small town. My Walmart no longer even sells one use grocery bags! They had signs up for a couple months before hand.

Tesco and Sainsbury's usually just have the bags at the entrance to the self checkout and you just scan the bag before using it.

They have a lot of self-checkouts in the UK - there's a member of staff on hand to help and they usually dish out bags although in some places you can just grab and scan a bag. If you wanted to not pay for one you could but the staff member and cameras are watching so it isn't all relying on honesty.