NEW YORK ( TheStreet) -- It's tempting. You're at the checkout counter ready to make a purchase and the clerk makes an enticing offer: "Save 20% today by opening up a store charge!" Although this may sound like a great deal, experts caution that credit cards aren't meant to be an impulse decision, and the perks are often short-lived. Even if you're eager for a discount, you should always find time to research the card you're applying for. Check out these five store credit card unknowns before you sign on the dotted line.
1. Opening up a store card can lower your credit score.
Requesting new lines of credit will ding your credit score, making future home loans and car loans harder to get and ultimately more expensive, says consumer saving expert Andrea Woroch.
Unfortunately, when you apply for a store credit card, there is a "hard inquiry" on your credit file, says Todd Albery, CEO of Quizzle.com. Applying for too many store cards can lower your credit scores because you're loading up on potentially damaging inquiries, he explains.
"Even if you open the store credit card just for the promotions and close the account soon after, your credit can still take a hit," Albery says. "A portion of your credit history is determined by your available credit, so closing an account you don't use can lower your score because you will lose the value of the credit limit."
Simply put, it's dangerous to open up cards on a whim, says Brian Kelly, founder and CEO of credit card comparison site ThePointsGuy.com.
"It's a hit on your credit, and you have to evaluate whether it's worth the benefit to do it," Kelly says.
2. The big savings are for big spenders.
Usually store cards offer a savings of 15% and 20% off your purchases on the day you open the card, but unless you're spending hundreds or thousands of dollars in a single day, you really aren't saving an enormous amount, Kelly says.
"If you are a luxury shopper dropping $15,000 and you can get 20% off, then that's a great deal," Kelly says. "But for most of us spending just a few hundred dollars, it makes more sense to take advantage of sign-up bonuses on traditional credit cards, which can be anywhere from $200 in travel points to $500 cash."
When you do the math, you realize you'd have to spend quite a bit on a store card to equal the sign-up bonus you can get from some of the best reward cards, says Gerri Detweiler, Credit.com's personal finance expert.
"Plus, with a new reward card you can use it anywhere that card is accepted, and not just in particular store," Detweiler says.