Each year the Revenue target specific industries for investigation; construction is always on this list. Now using historic online CIS returns they are able to data mine submissions in real-time looking for hallmarks of employment. These include:

1. Sub-contractors with only one employer
2. Sub-contractors who are paid regular amounts
3. Sub-contractors receiving few payments for materials
4. Sub-contractors who pay no other sub-contractors

Any contractor engaging these types of sub-contractor is flagged as a potential target.