Dear Saswata ji,
Let me repeat it, this system of not registering the IP with every new employment is not a new. It is not on IT roll out but since beginning.
Before IT roll out, we used to give to the Corporation Local Branch only the ESI number of the new employee who is already registered with earlier employment and the Local Branch was getting the details of the IP's contributions during previous contribution period from his previous concern Local Branch.
Due to this system, the IP was able to claim the benefits under this Act from day one if he has contributed in the previous contribution period.