Decorus Essentials and Decorus Professional both support Sage v16 onward (2010 to 2018). Each version has a different 3rd party integration key so this will need re-entering into the software once it is installed. The 3rd party integration is separate from you license key and you get it by going to - https://my.sage.co.uk/public/help/askarticle.aspx?articleid=9342ringingor or calling Sage support on 0845 111 6666.
Please see the attached document for further information on upgrading your Sage version.