Created a new IP and filed his contribution for 6 months - Deletion of duplicate IP?

Actually I have created a new IP and filed his contribution for 6 months. But now he says that he already has an ID from his previous employer and one of my co-worker has create a new ID with his previous ID. So, there is now two IDs of single employee. Kindly assist what to do???

ask the employee to visit the local office with both, ESIC will merge both IP numbers and his old IP number will get visible in employer's portal, including the payment made in new IP number

if the employee goes to get Smart card, bio metric formalities are done, and they find the duplicate on spot, earlier one get validated and the later one is merged always
ESIC Local office as Regional office is authorized to do it,
get your latest TIC duly attested by employer with family photo attested by employer along with TIC for getting smart card
Please find ESIC IP contribution transfer form