With Christmas just one week away, the U.S. Postal Service is hustling to make sure holiday cards and packages are delivered on time.

Monday is considered the busiest day for mailing holiday cards, letters and packages. That means longer lines at the post offices and frustration from customers. In an effort to expedite the process, the postal service is asking customers to make sure their package is wrapped properly and that it complies with all restrictions on height, weight and width.

Customers are also reminded to make sure the address on their package is legible and that they don’t forget the ZIP code. A missed ZIP code could mean the difference between the package arriving on time, and a ruined Christmas.

Customers are also asked to keep in mind exactly how much postage is needed to send their package.

Lastly, customers are also encouraged to track their package using email or text message alerts to make sure their package arrives on time.

If you are sending something through first class mail, you have until Tuesday, December 19 to send it to make sure it arrives for Christmas. Priority mail packages have until Wednesday, December 20. If you are sending mail via Priority Express Mail, you can procrastinate until Friday, December 22.

The main post office on Loyola Avenue will be open Monday through Friday from 7 a.m. to 7:30 p.m. The location will also be open Saturday from 8 a.m. to 3 p.m., but closed Sunday and Monday.