It’s that time again — time to shop for holiday gifts, ship packages to loved ones and hope they arrive in time.

Whether you send packages via the U.S. Postal Service, UPS or FedEx, you may need to keep an eye on shipping costs, deadlines and estimated delivery times.

You can ship packages late into the month of December, but you could end up paying more for faster shipping to get packages there in time.

And even if you ship early, your shipping costs could include peak surcharges imposed amid heavy demand for holiday shipping. UPS, FedEx and the Postal Service each have certain peak surcharges or higher rates for the holiday season.

Joshua Colin, the Postal Service’s chief retail and delivery officer, said in a written statement that “we are ready and confident to handle the holiday surge.”

But shipping delays are already prompting concerns ahead of the holidays.

Delayed mail continued through this year’s election and beyond, prompting Georgia senators and congressmen to question U.S. Postmaster General Louis DeJoy about the problems in Congressional hearings this month.

Here are some of this year’s major holiday shipping deadlines:

U.S. Postal Service

Recommended send-by dates for Lower 48 States for expected delivery before Dec. 25:

Ground Advantage Service: Dec. 18

First-Class Mail Service: Dec. 18

Priority Mail Service: Dec. 19

Priority Mail Express Service: Dec. 21

UPS

Recommended last days to ship for U.S. Domestic shipping for Dec. 24 delivery:

Ground: Check ups.com/ctc to calculate time and cost

3 Day Select: Dec. 19

2nd Day Air: Dec. 20