While many of us are making merry, it’s hardly the most wonderful time of the year for the accounting staffs at many small businesses.

A rush by employees to submit their expense claims so they can be reimbursed before the holidays, makes today the busiest expense-filing day of the year, according to data from online accounting services firm Concur (NASDAQ: CNQR).

On this day U.S. small businesses will process more than twice as many expense reports as the daily average. That’s a lot of unhappy accountants.

Putting off those expenses has a whole host of repercussions, including paying more money in federal and state taxes.

“It’s like sitting in a car and letting someone drive you down the Autobahn going 80 miles an hour with their eyes are closed,” said Nicole Fende, a financial consultant and president of the Small Business Finance Center. “You’re going to crash and it’s going to be bad.”