ESIC and PF - Should the firm take any kind of letter from the employee wherein he confirms his salary has increased?

The firm has esi and pf. The firm had three employees in the pdf category who left the firm last month, and other employees are in the epic category only or above the 21k limit and were never part of pf since they had wages above 15k. Shall the firm file nil return for pdf from now? Will the firm have any issues from the department if it files nil return in pf? Also, one employee's wages increased above 21k this month., so his ESI should stop in April 2024. Should the firm take any kind of letter from the employee wherein he confirms his salary has increased? Please clear these 2 doubts.

yes you have to confirmed the employees and also issued the increased salary letter. Also you have to informed the PF department about employees.

If there is no employee covered under EPF, then you can start filing Nil Return and pay the minimum administration charges as applicable. It is Rs 75 as there is no contributing member. There is no separate communication to be sent to EPFO but the date of exit marked in ECR or form 10 would be sufficient.

The employee whose salary exceeds in January should continue in ESI till March and from April onwards he can be excluded. In the monthly return of April he can be shown as 'out of coverage'