Maryland has a reciprocal agreement with Delaware. For the Master Plumber and Gasinstaller license, you can only apply online or call the State Board of Plumbing to get an application. The Washington State Department of Laboratories and Industries (DLI) has issued a notice on a reciprocal agreement between Washington and Oregon, which allows qualified electricians to obtain a transnational license. Read the full version here. Click here for more information on Mississippi`s mutual agreements….