Turn the check over and look for a line labeled "Endorsement." It will be located at one end of the check.
Write "Pay to the Order of" then fill in the name of the individual or organization who is taking ownership of the document. Use a name that corresponds with their identification. For example, if signing the check over to your married sister, use the last name on her driver's license. If she goes by her married name, that is what you should write.
Sign your name under the restrictive endorsement. The name you sign must match the name on the front of the check. If the check is made out to "John Q. Public", do not sign "John Public".