You can complain to the Commissioner about:
issues with MSPs’ registration or declaration of financial interests (sections 1-3 of the Code of Conduct). For example, if an MSP hasn’t registered or declared a financial interest (like shares in a company)
paid advocacy (section 4 of the Code of Conduct)
lobbying and access to MSPs (section 5 of the Code of Conduct)
You can also make a complaint to the Commissioner about an MSP’s general conduct in relation to some of the areas set out in Section 7 of the Code of Conduct:
treatment of other people
use of parliamentary staff
the confidentiality rules
MSPs’ responsibilities to their own staff
The Scottish Parliament does not deal with these types of complaints.