Just be aware that many stores want you to unload your cart onto the counter before you start to check out. All stores keep a clerk standing by to answer questions, so don't worry about being trapped in the system. Yes, you can scan coupons . Yes, many will weigh produce. No, you can't buy cigarettes or alcohol, unless a clerk is nearby to check your driver's license.
Stores have different policies and different machines .
Some allow a purchase of only 15 items or less. Others let you ring up larger orders, but have a clerk nearby to take your cash, check or bank card. Still other machines take the money and make change, just like a soda machine. Most close the self-checkout line in the late evening, since business is slower. The scanning system is slower than you think .