While you can't count it as a tax deduction, White Castle is offering customers a 15-percent discount on all orders at White Castle restaurants starting today through tax day on April 15.

"We want to satisfy the cost-saving needs of our Cravers this tax season," says Jamie Richardson, vice president of White Castle. "Whether you're still crunching the numbers or you've filed well before the deadline, we're happy to celebrate the end of tax season with you."

The coupon will be posted on the White Castle website. Customers can download and print it or simply show the coupon on their phone to receive the 15-percent discount.

"For anyone looking to prepare for 2015 charitable deductions—we also offer Autism Speaks puzzle pieces," Richardson says. "Throughout the month of April, which is designated as National Autism Awareness Month, White Castle will collect donations in $5, $3, and $1 increments."

Last year White Castle donated more than $650,000 to Autism Speaks by selling Puzzle Pieces for five weeks. This year, each purchase of an Autism Speaks puzzle piece also comes with a coupon for one free Chicken Ring Slider good for a future visit.