(CNN) - It is starting to get down to the wire if you need to send Christmas gifts.

According to the Postal Service , packages must be mailed by Wednesday to be delivered before Christmas.

If you pay for Priority Mail, you have until Dec. 18 to mail holiday packages.

Priority Mail Express Two gives you until Dec. 20 to get gifts in the mail.

Keep in mind these are estimates, and it’s always better to mail them a bit earlier.

Also, allow an extra day or two for items mailed outside the continental United States.

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