The holiday season is upon us, which means it’s time to start shopping for gifts and planning how to get them to your loved ones.

If you plan to ship packages through the U.S. Postal Service (USPS), it’s important to mail them out early enough to be delivered by Christmas.

The Postal Service recommends the following mailing and shipping deadlines for expected delivery by Dec. 25 to Air/Army Post Office/Fleet Post Office/Diplomatic Post Office and domestic addresses:

Dec. 9 — APO/FPO/DPO (ZIP Code 093 only) Priority Mail and First-Class Mail
Dec. 11 — APO/FPO/DPO (all other ZIP Codes) Priority Mail and First-Class Mail
Dec. 14 — USPS Retail Ground
Dec. 18 — APO/FPO/DPO (except ZIP Code 093) USPS Priority Mail Express
Dec. 20 — First-Class Mail (including greeting cards)
Dec. 20 — First-Class packages (up to 15.99 ounces)
Dec. 21 — Priority Mail
Dec. 23 — Priority Mail Express

The Postal Service’s busiest time of the season is two weeks before Christmas, when much last-minute shopping begins. Customer traffic is expected to increase beginning Dec. 9, while the week of Dec. 16 is expected to be the busiest time for mailing, shipping and delivery. Additionally, the Postal Service predicts that nearly 2.5 billion pieces of First-Class Mail, including greeting cards, will be processed and delivered the week of Dec. 16.

The Postal Service says it will expand Sunday delivery beginning Nov. 24 to locations with high package volumes. USPS already delivers packages on Sundays in most major cities and anticipates delivering more than 8 million packages on Sundays in December.

Some tips from USPS:

• Use free Priority Mail Flat Rate boxes. They are available at local Post Offices or online at usps.com/free boxes
• Make it easy with Click-N-Ship. You can create shipping labels and pay for postage online at usps.com/ship.
• Schedule a free Package Pickup when the carrier delivers your mail. It’s free regardless of the number of packages. Pickups can also be scheduled at usps.com/pickup
• New this year, mail and packages weighing more than 10 ounces and/or are more than a half-inch think using stamps as postage cannot be dropped into a collection box or left for a carrier to pick up. Instead, take them to a window clerk at a Post Office. Click-N-Ship customers are unaffected by this change.

Click here to learn more about Holiday Shipping with USPS.