The Reason Leaving The Customer Copy Of A Receipt At A Restaurant Is A Bad Idea
Dining out at a restaurant is a great way to celebrate or just relax, but it still requires a dose of common sense. You would send back your meal if it wasn't fully cooked rather than eat it and get food poisoning, and the same care is required for your finances. The main thing to remember is not to leave the customer copy of your credit card receipt at a restaurant, and really, there are multiple reasons for this.
Most people don't fill out the customer copy, so leaving a blank one gives an unscrupulous waiter the opportunity to adjust the tip in their favor after you leave. Additionally, if you have any problems with unauthorized charges from the restaurant, it will be significantly easier to dispute the charge if you have the receipt that tells you exactly what you spent (via Southern Living).
Potential for credit card fraud when dining out
Receipts are generally designed to ensure your privacy. That's why the credit card number is always listed with an "X" in place of all but the last four numbers. However, that is another reason not to leave your receipt behind. While those last four numbers won't let someone use your card to make unauthorized purchases, it could be enough for scam artists to use as a phishing tool to get the rest of your number (via Credit Cards).
As a rule, your credit card company will never ask you for your whole card number, so any calls asking for that information should be treated as suspicious. You can call your credit card company using the customer service number provided on the back of the card to make sure you are really talking to the company.
Another potential problem comes if you forget your credit card at a bar. When you go back to get it, you might find a "walkout" fee was added to your bill. As long as the bar has posted this information, such as on a sign, this is legal (via Lifehacker).
To avoid all of these problems, just remember to always take the customer receipt with you — it's just smart financial management.