You will be informed probably by mail from Walmart that your check has bounced and the procedure they have to pay it off. It may vary from store to store but in general you'll simply go to the store service desk, tell them you have a bad check to pay off, tell them your name and in a few minutes someone from the office will retrieve the bad check for you and give it to you in return for your money to pay back the check amount. There will be an additional amount charge for the extra handling which may be around $25-this varies by state so you need to be aware of that before you go. Your own bank will charge you an overdraft fee for the bounced check too. If you don't correct this quickly they may keep charging you on a daily basis which gets to be a lot of money quickly AND it makes the likelihood that all the other checks you've written will bounce too which snowballs into their own problems. So get this fixed quickly because it does get expensive really really fast. I think Walmart only holds the check for a few weeks before it turns it over to a collection agency which can charge you even more to repay it back, who may also report this to all the major credit reporting agencies (which hurts your credit score and all the fallout from that for years after) not to mention that most of these companies are fly-by-night and can easily screw you over in numerous ways if they aren't an honest company. Am I painting a crazy picture? I am-just to show you how out of hand one bad check can be to you at it's worst. Don't let it get that way. Always know the balance on your account and never write a bad check. The fallout from it isn't worth the cost. Only spend what you have and live within your means-a few things to live by your whole lifetime.