Keep those credit cards warm.

Retailers hoping to extend the Christmas buying frenzy will swing their doors back open Tuesday — with some offering Black Friday-level prices to clear inventory and keep registers ringing.

From Amazon to Nordstrom to Old Navy, an increasing number of outlets are offering fresh sales after the Christmas rush to lure consumers before their spending hibernation.

“A lot of people are going to be returning things, so I feel like it will be cheaper,” said teacher Ronny Rahman, 35, as he strolled Fulton Street in Brooklyn on Monday. “I feel like now is a good time to get it.”

Beginning Tuesday and extending through Jan. 2, Nordstrom will offer new sales on clothing and accessories both in stores and online.

Old Navy is touting price cuts of up to 70 percent after Christmas, and e-commerce king Amazon plans a slew of special deals in the coming days.

Retail experts have projected robust holiday sales this year with a booming stock market, a rosy economic outlook and the prospect of impending tax cuts.

Retailers are casting a wide net to ensnare shoppers expected to head right back to the local mall to return unwanted items or to use gift cards.

Some shoppers were already poised to pounce on Dec. 25 itself.

Banker Andre Silva, 30, of Brooklyn, was disappointed to find the Atlantic Terminal Mall and a B&H store in Manhattan closed. “I’m preparing,” he said Monday.