The main difference between certified and registered mail with the U.S. Postal Service lies in the level of accountability, with registered mail being tracked throughout the entire process from the departure point to the destination. Both types of mail are numbered, but certified mail is only signed for once it reaches the final recipient.
Registered mail costs considerably more than certified mail, approximately four times as much. Both can be tracked online by anyone with the official tracking number. This provides a record of attempted deliveries and verification of final successful delivery. Registered mail includes a return receipt and the option for restricted delivery to a specific recipient. Certified mail offers these two options for an additional charge. Registered mail can be insured against loss or theft, while certified mail does not carry this option.