IS PF sub-code is mandatory for contractors

Respected seniors
This is Ramu working as DM-HR in manufacturing sector. My query is that we have engaged one contractor (L&T) for plant expansion project. As per our terms and conditions PF & ESI Employer contributions will be reimbursed by the company on submission Paid challans & ECR files. As per our advise L& T has got ESI sub code at Sub Regional office which our industry in the coverage limits. Whereas PF L&T is paying in the main code which is large number of employees including other areas contract employees. L&T is engaging around 2000 workmen in our premises for expansion project. PF ECR files which is submitting by the L&T having more than 10000 employees.
Can we advise the contractor to get the PF Sub code ?
Ramu

for EPF, the contractor can submit the selective employees ECR seperately, under their main code , it wil generate a separate ECR for those employees who are engaged in your place,
no need to get sub code
even in case of ESI, in specific circumstances, they could provide employees with their principal code, without getting sub code.

The sub-code for a sub-contractor is needed where such contractor does not have PF Registration (PF Code). But if the sub contractor is an establishment covered under the PF Act, it has no need to contribute to PF under the L&T code, rather it can avail its own code. Since L&T is having only 2000 workers out of the 10,000 for which it is complying, it means most of the other contractors are big and has numerical strength sufficient to attract PF coverage. Furthermore as regards these contractors are concerned they will have a tough time convincing the PF Inspectors of having complied with PF provisions for these labourers through L&T Code. From experience it can be safely said that as far as principal employer is concerned (which you are in any case) and so far as the labourers of these contractors are concerned, it is better that the PF is complied at the respective contractor level. But as regards any contractor not covered under the PF Act, there is no go except getting them covered under the code of L&T.

Thank you sir for your valuable advise on my query