Question - Is it correct NAECI sites only allow direct employ?
Answer - Yes
The NAECI is founded on the principle of direct employment. The signatory parties affirm their commitment to this principle.
Accordingly, all individuals employed on work within scope of the NAECI by companies in membership of a signatory employer association shall be employed directly, in full compliance with NAECI terms and conditions.
Note: Where individuals are subject to United Kingdom income tax and social security, 'direct employment' for these purposes means employment (on a contract of employment) to which PAYE income tax and Class 1 national insurance contributions are applicable. All forms of self employment are expressly prohibited.