Understanding CTC Basics: Is It Necessary to Keep 51% for PF Calculation?

The PF officer insisted on keeping basic as 51% of fixed CTC (fixed CTC = Gross salary + PF employer contribution + Gratuity Contribution).

Doubts:

1) Can we keep gratuity contribution as a part of fixed CTC?
2) As PF is calculated on the increased basic take-home, have been reduced. Is it mandatory to keep basic as 51% for PF calculation?

Please reply ASAP.

There is no ruling or act on the percentage of basic in CTC. It is generally considered as 40% for non-mentors and 50% for metro.

There is a risk in showing gratuity in CTC. Many employees have claimed gratuity after 3 or more years of service since it was shown as part of CTC.

No, but as per the new PF rule, the definition of "wages" to be considered for PF has been changed. So, whether that can be the reason why we should show basic at least 51% so that for PF deduction at least 51% is considered. ????