The U.S. Postal Service is preparing for its yearly rush.
The agency said Monday, Dec. 15, will be the busiest mailing day of the year, with over 640 million cards, letters and packages expected to be processed.
By comparison, the agency handled 607 million pieces of mail during the 2013 holiday season. The increase can be attributed to growth in advertising and mail package volume, the agency said.
To handle the increase, the Postal Service will be delivering seven days a week in major cities and high volume areas. This also means deliveries on Christmas Day.
To ensure deliveries arrive in time for Christmas, customers must send their greeting cards, packages and letters by Dec. 20. Meanwhile, the deadline for sending packages using Priority Mail Express is Dec. 23.