Get ready because your employees are going to start throwing a lot of expense claims at you pretty soon. If last year repeats itself, the busiest day for expense claims will be the third Monday of December, Dec. 15.

That's according to spend management company Concur, which today released new analysis of business expenses that shows some pretty interesting trends. 

"Knowing what lies ahead is the first step to streamlining expense processes," Concur vice president Neil Charney said. "Our data shows that this is a critical time of the year for employees to tackle the back-log of expenses." So if you want to give your finance department a gift this holiday, try encouraging employees to submit their expenses now before the third week crunch. 

The report also revealed that, not surprisingly, lodging, airfare, and meals made up 93 percent of all expenses. Lodging accounted for more than $57 million of expenses, airfare accounted for more than $57 million. Meals and phone expenses took up the third and fourth largest amounts of expenses, respectively.

Much of the analysis pointed to the fact that expenses are becoming more and more digital. Last year, the daily averages for submitting expenses on Web and mobile hit an all-time high. The numbers on the third Monday of last year, Dec. 16, were especially high, with more than half a million receipts uploaded on Concur's mobile app.

Four industries, in particular, made up a large chunk of that mobile expensing. Pharmaceutical manufacturing accounted for 12.7 percent of mobile expensing, industrial manufacturing accounted for 8.5 percent, health care accounted for 8.3 percent, and retail accounted for 6.7 percent.

Tell us in the comments: Are you still processing expense claims manually, or have you switched to a paperless system?