Where and when to snag sales tax breaks across the US
Consumers looking for deals on their back-to-school purchases don't need to rely on retailers for all of their cost savings.
Several states will once again offer sales tax holidays during the critical back-to-school shopping period—the second-largest selling season of the year—in an effort to lure customers into stores.
"Sales tax holidays are very, very popular with consumers and very successful at getting consumers into stores and getting them to spend money," said J. Craig Shearman, vice president of government affairs public relations at the National Retail Federation.
Read MoreParents, get ready to spend more on back-to-school
But the impact goes far beyond money, Shearman said. If a retailer were to offer 5 percent off a purchase, consumers—who are used to seeing double-digit discounts in store windows—would laugh. But because the discount relates to not paying a sales tax, it has a psychological appeal, he said.
"Americans have hated paying taxes back to the Boston Tea Party," Shearman said.
(To see which states will offer sales tax holidays and when, as well as what items are included, see the infographic below.)
Seventeen states will hold sales tax holidays this year, with each state offering its own criteria for qualifying purchases. In Louisiana, for example, there are few exclusions on purchases up to $2,500. In Oklahoma, on the other hand, the exclusions mean the tax break applies only to clothing and footwear that cost less than $100 per item.
Despite these complexities, Charles Maniace, director of tax research at Taxware, a software provider that works with a number of top U.S. retailers to ensure their point-of-sales systems are compliant, said consumers are well-versed in the deals offered by their state.
Read MoreRetail crosses a line with back-to-school deals
"If they're going shopping, they absolutely know what the rules are and they will hold retailers [accountable]," he said.
But while sale tax holidays are popular with consumers, critics argue that they do nothing to stir economic growth, and they simply shift spending on already planned purchases. One of these organizations is the Institute on Taxation and Economic Policy, a nonpartisan group that said sales tax holidays will cost states at least $300 million in 2014.
"Revenue lost through sales tax holidays will ultimately have to be made up somewhere else, either through painful spending cuts or increasing other taxes," the institute said in a recent report.
North Carolina, the only state that participated in a sales tax holiday in 2013 but will not do so this year, decided to repeal the legislation, opting instead for an income tax cut.
The move "more than offsets the one-time savings obtained during promotional sales tax holidays," state Rep. David R. Lewis said in an email.
Shearman, on the other hand, said the events typically end up being a wash for states because they come with restrictions. Governments, he said, make up lost revenue from consumers purchasing items that are not included in the exemptions, and from shoppers who use their savings to make additional or higher-cost purchases.
Matthew S. Walsh, vice president of tax research at Taxware, said there's also a belief that people who are out shopping spend more by dining out, and that states receive higher income taxes from people working extra hours to accommodate the increase in traffic.
On the other hand, for families who are just "scraping by," the holidays may be a way for them to purchase everything they need to buy their kids for the year, Shearman said. According to a survey by the National Retail Federation, the average family with children enrolled in kindergarten through high school will spend $669.28 on back-to-school purchases.
Read MoreAmazon doesn't always offer the best deals
What's more, 8 in 10 respondents told the federation the economy will impact their spending over the period, with 34 percent saying they will buy store-brand items for school, and a quarter saying they will make due with last year's items.
"[Sales tax holidays] may be the little edge that helps parents afford what they need to buy," Shearman said.
—By CNBC's Krystina Gustafson.