Dear Vinod ,
PF is deducted on Basic pay. Below is the definition of Basic Pay.
‘Basic pay' :- means all emoluments which are earned by an employee while on
duty or on leave or on holiday with wages in either case in accordance with the terms of
the contract of employment and which are paid or payable in cash to him but does not
include -
(i) the cash of any food concession
(ii) any dearness allowance (that is to say, all cash payments by whatever
name called paid to an employee on account of a rise in the cost of
living), house rent allowance, overtime allowance, bonus, commission
or any other similar allowance, payable to the employee in respect of
his employment or of work done in such employment.
(iii) any presents made by the employer.
Source
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Regards
Krishna