Hi @conalld-codelect
If you have retained your individual CIS registration then, yes, you can 'moonlight' from your day job in just the same way as any standard employee.
Where you might come unstuck (from HMRC's point of view) is using company resources for your private jobs - especially if both are in the same line of work. This would include not only tools & consumables but also information. If the company is paying for advertising, for example, the benefit of that must go to the company.
You can't have expenses being paid by the company but profit being taken personally. That's why most people would route every job through the company - it quickly becomes a minefield otherwise.
Hope this helps.
