Any item for which first-class postage has been paid, including Priority Mail, can be certified for an extra fee. Certified mail is one of several categories of "accountable mail," meaning that each piece of mail is identified and can be tracked by the sender, and that the item must be delivered in person. Senders can also purchase additional services to restrict delivery to only the specific addressee or to have a signed receipt mailed back. When certified mail can't be delivered in person, the letter carrier will leave a copy of Form 3849, which includes instructions for arranging redelivery.
Items you will need
USPS Form 3849, showing the origin and nature of certified mail addressed to you
Read near the top of the form what time the item will be available at your post office (when your letter carrier is expected to have returned from your route). If it's past that time but the post office is still open, you can go there, present and sign Form 3849 and any return receipt the sender has requested, show photo ID and receive your mail. Unless the dash next to "Restricted Delivery" on the left edge of the front of the form is marked, you can send someone else to pick up the item for you. Sign in the left column on the back of the form and print your "agent's" name in the larger space.
Print your name and sign in the spaces indicated on the back of the form and check the box requesting redelivery. Leave the signed form in your mailbox. This will take at least two mail-delivery days, since your letter carrier will leave the certified mail at the Post Office until your request for redelivery and your signature are presented there. You can also specify, near the check box, a day for the item to be redelivered with your regular mail. If "Restricted Delivery" is indicated on the front of Form 3849, you will need to be present to receive the item in person.
Enter your ZIP code to enter the USPS.com online redelivery service (see Resource). Fill in your name, address and phone, confirm them and copy the article number(s) for your mail from the right column of the front of Form 3849. Check other appropriate boxes to complete your request. Indicate the day you will be available to sign for your mail at your regular delivery time. If you submit an online request, or phone 800-275-8777 (the USPS Customer Service line), by 2 a.m. Central time, you can request redelivery at your next regular mail delivery.
Someone to whom certified mail is addressed can refuse delivery of the item, and the Postal Service will return it to the sender. To have a refused item redelivered, the sender must repackage it and pay new postage and fees for certification.