As per the PF Act,
Employee Definition:
"Employee" as defined in Section 2(f) of the Act means any person who is employed for wages in any kind of work, manual or otherwise, in or in connection with the work of an establishment, and who receives wages directly or indirectly from the employer. This definition also includes any person employed by or through a contractor in or in connection with the work of the establishment.
Membership:
All the employees (including casual, part-time, daily wage, contract, etc.) other than an excluded employee are required to be enrolled as members of the fund on the day the Act comes into force in such an establishment.
Even though employees working on a piece-rate basis, their PF deduction is still mandatory. If their PF is not deducted, it constitutes a statutory violation by the principal employer.
Therefore, it is advisable to deduct the PF and ESI amount from their monthly bill and deposit it under your company's PF and ESI code. Alternatively, you can have a new PF and ESI code solely for subcontractors and deposit their amount under that code (preferred).
If you require more information, please feel free to discuss.
Regards,
Ratikanta Rath