The term Principal employer is usually used in relation to an employer who appoints employees through a contractor. Basically, there is no difference between the terms- Employer and Principal employer. When used in the context of contract employees, it becomes principal employer. As all employees (subject to the wages ceiling fixed under the different legislations) whether directly employed or through a contractor are working for the employer, it is his responsibility to implement the labour enactments in his establishment. Accordingly, the employer has to remit the PF dues of his employees in time and recover the employees' share from the salary of the employees. Similar is the case of ESI. At the same time, it becomes the responsibility of the Principal employer (for whom the contracted employees work) to remit the EPF, ESI, etc., of the employees employed through a contractor and certainly he can deduct the same - both shares - from the payment to be made to the contractor. That means though contracted employees are employees of the contractor but are working for another and that another person, the principal employer, is responsible for the initial payment of dues and they are recoverable from the contractor as if he had made the payment of ESI or PF on behalf of the contractor.
The word "occupier" is also used in certain Acts such as Factories Act, Payment of Bonus Act, etc., which has the scope of Principal employer.
The Principal employer is responsible for the implementation of labor welfare and social security measures provided under different labor and factory enactments.
Regards,
Madhu.T.K