NEW YORK ( MainStreet) — As holiday shopping season hits high gear, the number of retail credit cards in use out there is also high — at 183 million, the most in use since 2009, according to credit analysis firm Equifax.

Consumers aren't shy about using them, either. Equifax says the total balances on those cards stands at $56 billion, up 6.4% from last year.

As retail card write-offs and late payments are down, card carriers have become open to issuing more credit to consumers, and that could be a win-win for shoppers and retailers.

"Retailers are eager to capture the hearts and wallets of the American consumer," Equifax chief economist Amy Crews Cutts says. "Retail cards are a great way to do both. Retailers can leverage these cards to drive traffic to their stores through special offers to cardholders and can encourage larger purchases by offering favorable interest-rate promotions for big-ticket items."

"As long as consumers resist the urge to overspend, these cards can be a great way to save money when holiday shopping," Cutts adds.

Consumer finance experts say it's all a matter of discipline and diligence.

"There are ways to use these credit cards and even get the 'instant discount' at the checkout without going into debt," says Beverly Harzog, a consumer advocate and author of the book Confessions Of a Credit Junkie , which was released this month.

By and large, consumers should be wary of the heavy payments linked to store-based credit cards.

"These cards are rarely a good deal for consumers because the interest rates can be very high," she says. "Often, a consumer will agree to get a retail card just for the instant discount when they pay for merchandise. But if that consumer carries a balance on a high-interest credit card, the discount won't mean squat. Really, it's never a good idea to agree to a credit card when you have no idea what the terms are."

Sometimes a consumer may decide a specific retail credit card will save them money. If "you know you won't carry a balance, but you really want the store instant discount to buy holiday gifts there," Harzog says, make sure to conduct some due diligence first:

  • Check the fine print. Go online and read the terms of the retail credit card that interests you before you go to a store and get offered a card while you're trying to buy your gifts. Or pick up the card information when you get to the store, before you hit the checkout lane.
  • Ask questions. What's the interest rate? Is there a grace period? Are the rewards worth it? Does this affect your FICO score?
  • Check disclosures. Read all of the disclosure statements so you can make an informed decision.

If you cover that ground, you'll be able to take advantage of the instant discount, because you've already done your homework, Harzog says.