https://forums.autodesk.com/t5/autocad-lt-forum/autocad-lt-2016-download/m-p/5787356#M67418 To quote Lynn:<BR />"If you have Maintenance Subscription, you need to request a different serial number for your 2013 version. Your current serial number will not work.<BR /><BR />If you have Desktop subscription, you will use the same serial number for 2013 version and it will display in your Autodesk Account."<BR /><BR />Which "if" are you? the answer is in her reply. Tue, 25 Aug 2015 18:30:36 GMT pendean 2015-08-25T18:30:36Z