Hawaii Certificate of Service is a document that attests to the successful completion of military service in the state of Hawaii. It is issued by the Hawaii National Guard and is used to verify a veteran's service for the purposes of obtaining veteran benefits, such as healthcare and educational benefits. There are two types of Hawaii Certificate of Service: the original and the duplicate. The original Certificate of Service must be signed by the veteran's commanding officer and must include all the veteran's information, such as name, service branch, and dates of service. The duplicate Certificate of Service is an exact photocopy of the original and is used to provide additional proof of service if needed.