If I already have a residence address registered with the DMV
you are not required to change it when you change your mailing address , but you can change the residence address if you want to
what is the document number
Document Number. The document number is 8 or 10 characters , and is printed on the lower right corner of your DMV photo document , or on the back for documents issues after January 29 , 2014 . The 8 character format is all numeric .