To avail deduction-
a) Employer's contribution to PF should be made on or before due date for filing the return of income.
b) Employee's contribution to PF should be made on or before due date under relevant Act.
As per the high court in the case of cit vs.aimil ltd employees contribution to provident fund, esi is allowed even if paid after the due date of relevant act but before the filing of return u/s139(1).