The holiday season is about to kick off, and those looking to send gifts and cards via the USPS should note new shipping deadlines for 2021.

For domestic delivery before Christmas (Dec. 25), the following deadlines apply, according to the USPS:

USPS retail ground service: Dec. 15
First-class mail service: Dec. 17
Priority mail service: Dec. 18
Priority mail express service: Dec. 23
If you’re sending gifts overseas, your deadlines will be much sooner. Most of the deadlines for the different delivery options land between Nov. 29-Dec. 13. You can confirm shipping deadlines for specific destinations here.

Remember that certain shipping restrictions apply, even to holiday gifts. Alcohol, perfume and cologne are restricted.

The USPS also warns to use new boxes, since old ones might be weak and easily damage during transit.