A product key is a unique 5-digit code used during installation to distinguish between a standalone software purchase and one that is part of a larger product suite. For AutoCAD 2013, the standard standalone product key is . Common AutoCAD 2013 Product Keys
(logging in with an email). If you are having trouble activating this older version, you may need to contact Autodesk Support directly to see if they still support activations for 2013. Activating a Single-User AutoCAD 2018 License product key of autocad 2013
If the standard keys above do not work, you can locate your specific license information through these official methods: A product key is a unique 5-digit code
Autodesk Registration & Activations: AutoCAD 2013 (900-46609521) product key of autocad 2013