The biggest day of the year for store returns is the day after Christmas, and while retailers work to accommodate the influx of shoppers at the customer service desk, they’re increasingly mindful that some may be naughty instead of nice.

This year, retailers estimate they will lose $2.9 billion due to fraud during the holiday season, according to the results of an annual return fraud survey from the National Retail Federation.

That’s 17 percent less than in the 2011 holiday season, when retailers estimated they would lose $3.5 billion due to return fraud, according to the NRF.

Retailers estimate 4.6 percent of holiday returns are fraudulent, the survey said.

At Sears in Springfield’s Upper Valley Mall, post-holiday returns peak immediately after Christmas but continue over a period of several days.

“People don’t want to get into all the crowds the day after Christmas,” said Darryl Yount, Sears general manager.

“I don’t think there’s a big problem (with return fraud), but as usual you have the occasional one here and there,” he said.

Yount said the store allows members of its “Shop your way” program the ability to return without a receipt. Other customers must show a receipt and return the items between 14 and 90 days depending on the department.

Retailers estimate that 13.4 percent of the returns made throughout the year without a receipt are fraudulent, according to the survey. As a result, 73.2 percent of retailers now require customers returning items without a receipt to show identification. Just 7.1 percent of retailers require customers making returns with a receipt to show identification, and 26.8 percent say they do not require identification during the return process.

When it comes to their company’s holiday return policy, most survey respondents — 83.1 percent — said their return policies will remain unchanged compared to the 2011 holiday season, and 10.2 percent said they will relax their policies to help ease the process for gift givers and recipients.

While stores such as the local Sears have more lenient policies for specific customers, other stores such as Target give all customers leeway with returns.

“We have a pretty lofty return policy,” said Jen Hausfeld, manager of a Target in Middletown. “We offer receipt lookup for guests who want to return (an item but) they don’t have a receipt.”

However, Target does take precautions by limiting the dollar amount of returns accumulated during the course of a year, tracking via identification how many returns are made per year by each customer and requiring a receipt for refunds on items that cost $70 or more, she said.

“Anything over $70 without a receipt is limited to just an exchange,” Hausfeld said.

Survey results show that retailers will lose as much as $8.9 billion to return fraud in 2012, according to the NRF.

“Return fraud comes in a variety of forms and continues to present challenges for retailers trying to grapple with the sophisticated methods criminals are using to rip off retailers,” said Rich Mellor, NRF’s vice president of loss prevention. “Even more troubling is the fact that innocent consumers often suffer because companies have to look for ways to prevent and detect all types of crime and fraud in their stores, oftentimes resorting to shorter return windows and limitations on the types of products that can be returned.”

This holiday season is shaping up to be better than last year’s but not as much as what it first projected.

ShopperTrak, which monitors store sales worldwide, said last week it was cutting its holiday buying forecast.

After initially projecting sales would increase 3.3 percent from last year, the Chicago-based company now projects retail sales will rise by about 2.5 percent. It ascribes the slowdown to the Newtown shootings and Superstorm Sandy, saying both have made a dent in consumer enthusiasm.

Staff writer Everdeen Mason contributed to this report