It appears that Sage wont give you access to that information as standard which,to me, is illogical. Especially if you have several users running off reports, it would be useful to print the user's name or id out.

The only place it is made visible is associated with Audit Transactions and reporting

So effectively, there isn't a table available in the Report Designer to add that field then?

Correct. Not unless Sage respond differently

I can confirm that user details are not currently exposed/available for reporting on via Report Designer. If people think this would be a useful addition please up-vote this so out product management team can prioritise accordingly.