FedEx predicts today will be the busiest in its history. The Memphis, Tennessee-based shipping company expects to move nearly 16 million items around the world. That’s a 12 percent increase over its busiest day last year, and double what the company ships on an average day.

“Continued growth in online commerce is a really a big part of it,” said FedEx spokesperson Carla Boyd.

Atlanta-based UPS and the United States Postal Service are also anticipating busy days ahead.

The USPS predicts December 20 will be its busiest shipping day of the year. Postal officials expect to process 800 million letters, cards and packages on that day — a 43 percent increase over the 560 million pieces it handles on an average day.

Atlanta-based UPS expects its busiest day of the year on December 22, delivering 24 million packages — a 59 percent increase over the company’s normal daily delivery of 15.1 million items.

UPS announced it hired 50 thousand seasonal workers to deliver an estimated 430 million packages between Thanksgiving and Christmas this year. FedEx said it does not release seasonal employment figures.

Although exact figures on seasonal hiring at the US Postal Service were not immediately available, USPS spokesperson Michael Miles said the numbers of seasonal hires for the 2010 holiday season were relatively small.

“Because we are under a nationwide hiring freeze, we did not do widespread hiring this year as in years past,” Miles explained in an email to FOX News.