I have a supplier that we buy materials from that will be used on jobs that we are carrying out within the CIS. 

When I receive an invoice from this supplier, I want to use to code it using the Cost of Sales code 'CIS supplies and materials', but to use this code the supplier needs to be marked as a CIS sub-contractor. 

I want to use this code so I can track what materials have been purchased for CIS jobs separately from materials purchased for non CIS jobs.

This supplier is not a CIS sub contractor. 

This creates an issue when trying to submit to HMRC the CIS suffered because it comes up saying that I have a sub-contractor supplier that is not verified. 

I can't understand why QB would not allow you to have a supplier that you buy materials from for CIS jobs that is not a sub-contractor.