The Certificate Number must be seven digits long. It may prove useful for authenticating a previously issued business registration certificate. What is a certificate of registration number?Ĭertificate Number: This number, sometimes called the "Sequence Number", is the unique ID assigned to each business registration certificate. To get started registering your stock certificate, you'll need to get the name of the company transfer agent, which is an entity separate from the company issuing. Patent and Trademark Office evidencing that a mark has been registered. A certificate of registration is an official document from the U.S.