Sir,
1. The new employer/management, in my opinion, can continue compliance under ESI Act, 1948 and rules/regulations framed thereunder on the old Code Number allotted to it. However, in case of past liabilities, kindly see Section 93A of the said Act.
2. In case of change of name of the unit/factory also, in my opinion, the same old code number can continue.
3. However, in order to avoid any doubt at the level of authorities, it is essential and important that the new employer/management may inform the Branch Office Manager, Social Security Officer & Regional/Sub/Divisional Office of ESIC to which the unit is attached regarding change of name of factory/unit by also enclosing with letter a copy of deed/ agreement etc. regarding such changes/transfer.
4. It is, however, also submitted that sub-code is issued on the basis of main factory/establishment, which is located somewhere in other region of ESIC. Therefore, in case only the Sales Office/Branch Office of a unit has been sold to other unit/owner, then in this situation, facts appear to be different and in my opinion, appropriate Office of ESIC as mentioned above may be consulted and approached for necessary orders in the matter.