Dear [Name],
As your company is the principal employer, the agreements drawn between your company and the contractor should be very clear on these statutory issues. You are also advised to collect the copies of Registration Certificates, i.e., relating to PF, ESI, PT, etc., and keep them for records. This will confirm that you have engaged a registered contractor in all matters relating to statutory issues.
By and large, the ultimate onus lies on the principal employer to discharge all such liabilities if notices are issued to contractors and they do not pay. One of the best practices some companies follow is to deduct such amounts and issue drafts favoring statutes, depositing them on behalf of the contractors.
I hope this clarifies your doubts. For any further queries, you are most welcome to ask.
Thank you.
Sincerely