The Department ID number entered here will be used in place of the federal Employer ID number. For the taxpayer identification on all business returns, the following order will be recognized: New Hampshire Department of Revenue Issued Identification Number (DIN). Per 2D barcode specifications, this number begins with NL followed by seven digits. Federal Employee ID Number (EIN). Social Security Number (SSN). If a valid Department Identification Number, Federal Employer Identification Number or Social Security Number hasn’t been entered, the New Hampshire Department of Revenue requests the taxpayer identification number fields be left blank and Form DP-200, Request for Department Identification Number, be included with the return when filed. Note: Form DP-200, Request for Department Identification Number (DIN), is available as a non-calculating form if you need to request a number.