Selling holiday gift cards? Beware of this scam.

The most difficult thing about choosing a gift card can seem like choosing one retailer from many options.

After all, which gift card will really please your tech-loving best friend—Amazon or Apple? How about a foodie partner? Should you go with DoorDash or a national chain like Olive Garden?

While you may be focused on personalizing your choice, there’s something you may not have considered at all: the possibility that someone has already collected the data they need on the back of that card to steal the money you’re going to put on it.

The problem with this nationwide real scam is that it sounds impossible.

But thieves, often members of organized crime networks, enter stores with gift cards, pocket multiple cards, and tamper with the packaging to steal the barcode and PIN that recipients use to unlock their card. Sometimes fraud occurs within the store itself, when a cashier switches your payment card for a dud during the checkout process.

Either way, when the recipient tries to access their gifted funds, the balance is confusingly zero.

The exact amount of gift card fraud is unclear, but if even 1 percent of the $570 billion in gift cards each year is stolen, that could put consumer losses at $5 billion, according to an estimate provided to ProPublica.

Other than purchasing a digital or electronic gift card directly from a merchant or brand, there is no guaranteed way to avoid becoming a victim of gift card fraud. But following these professional tips can add layers of protection:

1. Check the gift card before you buy it.

Some scammers have gotten so good at tampering with gift cards that consumers don’t know the difference. While legislation passed in Maryland this year could ultimately improve the security of gift cards nationwide, the products are still at risk of disruption.

That’s why the Federal Trade Commission recommends making sure the card still has its security sticker, and that it doesn’t appear to have been tampered with. The rear pin should also not be visible. If you suspect that the card has been stolen, give it to the store employee and choose a different one.

2. Keep a copy of the gift card and store receipt.

The FTC recommends taking a photo of both the gift card and your purchase receipt. The card information, along with the transaction data on the receipt, can help you report fraud to both the gift card company and the store.

The FTC maintains contact information for the major gift card companies. If you don’t see your card’s contact information on the FTC list, try using the information provided on the card itself. Report to the FTC if the card issuer can’t be reached or refuses to talk to you.

3. Buy gift cards from trusted retailers.

You may be tempted to buy a gift card from an online auction site or third party, but their offer may be fake or stolen. For added peace of mind, Jory MacKay, head of content planning for online security brand Aura, recommends buying gift cards directly from the brand’s website.

4. Buy a gift card using a credit card with fraud protection.

If you have a credit card with fraud protection benefits, MacKay suggests using it to purchase a gift card. That’s because credit cards generally offer better protection against unauthorized charges and may come with a $0 fraud penalty if you’re defrauded. Be sure to keep the receipt as it will contain information you may need to share with the credit card company.

5. Consider buying multiple gift cards instead of one card for a large amount.

Sure, it can be satisfying to give a loved one a gift card at an amazing value, but buying a number of smaller cards instead can be a smart move, says MacKay. This way, your loss may be less if you buy a card that has been unknowingly issued.

6. Register the card online, if possible.

You can register for gift cards online, which often offer more security and options to freeze the card or track the balance, MacKay says. It is also easy to report an issued card once it has been registered.

7. Quickly use up the card balance.

When you give the card to the recipient, you can gently encourage them to use the balance sooner rather than later, and register it if they haven’t already.

MacKay says unused cards are more vulnerable to theft and fraud.

If the gift card has a zero balance, MacKay recommends checking it first to make sure you have a receipt.

Then, contact the merchant or card issuer. They can help you determine if the card has been removed or tampered with before making a purchase. MacKay says trusted stores and brands are more likely to return the card, especially if you’re quick to report the problem.

“The key is to act quickly—preparing the matter early can help ensure your recipient gets the full value of their gift,” says MacKay.