The United States Postal Service in Arizona will see their busiest shipping day Monday.
Arizona USPS will handle 3.3 million pieces of mail, as in letters, and 15.3 million packages.
In the 2014 holiday season, U.S. Postal workers saw a record number of packages, due in large part to a boost in online shopping.
USPS worker Julie Utley said she expects the record to be broken in 2015.
"We're anticipating ten percent above last year's packages," Utley announced.
Tuesday will be the cut off day for guaranteed Christmas delivery for standard shipping. That's why Tamra Wagner dropped off her packages Monday.
"I'm shipping Christmas gifts for my family," Wagner said.
Due to the increased volume, several Valley locations will have extended hours and some will be open on Sundays. Packages will be collected in special blue boxes.
The future deadlines for Christmas delivery are Dec. 19 for First-Class Mail, Dec. 21 for Priority Mail and Dec. 23 for Priority Mail Express. Prices are expected to increase as Christmas Day approaches, so USPS suggests shipping early and making sure all boxes are sturdy with proper labels.
Utley suggests buying labels online, as they may be cheaper than in the Post Office.
Sunday pickup locations: