Can Unregistered Contractor Have 9 Worker Pay P.F. under another Contractor P.F. Code ?

My Friend is contractor of labour and having 9 labour he was paid p.f. of his labour to under another registered contractor p.f. code,please help me it is true practice?

If a contractor engages 20 or more workers in any establishment he has to apply for a PF code number and obtain the number and start contributions in respect of his employees to PF authorities.
It is advisable to obtain an independent code number rather than remiting contribution through another contractor's pf code (not a correct practice).