PF disallowance

Employer Contribution disallowed u/s 43B if it is not paid within due date of filling of return of Income i.e 30th September

However, deduction cannot be claimed if the employee’s contribution to PF is deposited after due date of filing the return as the provisions of section 43B does not apply to employee’s contribution towards

Under Sec.43B, due date is the date of filing return of income. For, employer's contribution, this date is relevant for allowing deduction.
But, for Employees's deduction, due date is the date mentioned under the relevant welfare Acts. So, here.. deduction is allowed even if deposit is made after due date mentioned in the relevant Act but, before the due date of filing return of income.

There are a few contrary decisions also, but payment during the grace period doesn't attract disallowance u/s 43B.