No doubt you’ve been in this all-too-familiar scene at a store: You’re ready to pay for your purchases when the store clerk offers you a discount—if you open a store credit card. Tempting as it may be to get that 20 percent off, don’t do it.
“When a credit card lender checks your credit history in order to approve you for a new card, it’s going to affect your credit score negatively, because you are applying for more credit,” says Herron. Put another way: You don't want to have too many credit cards. Furthermore, most of these specialty store cards come with low credit limits and high interest rates. “So unless you pay off your balance in full, the discount is gone with the interest you incur,” says Herron.
Finally, if you don’t use the card after the initial purchase, you run the risk of the lender closing the account—which can further hurt your credit score.