(NewsNation) — When checking out during your holiday shopping spree, the clerk may ask, "Would you like to save on today's purchase by signing up for a store credit card?" The offer can be tempting, especially when the sticker shock of the total sets in. So, should you open a store credit card for a one-time purchase? What is the ideal number of credit cards? According to NerdWallet, the offer is usually better for the issuer than the cardholder. Interest rates for retail credit cards are generally higher than other credit cards. They also have a "lower-than-average" credit limit. Some can be used at only the store that issued the credit, so you may find yourself shopping for unnecessary items and racking up debt you can't pay. Also, signing up for a new line of credit affects your credit score. Store credit card debt: Can it be forgiven? On the other hand, some retail cards offer long-term in-store discounts beyond the one-time savings upon signing up, which can be attractive to some consumers. Plus, department store cards can be a way for people to improve their credit -- as long as they make on-time payments in full. "Just be sure not to sign up for cards at too many 'favorite' stores," according to NerdWallet. "Having many credit accounts increases the risk of overspending if you use them, and the risk of identity theft if you don’t."