I agree, encashment is permitted only at the time the employee leaves the company, as you said, at the time of full and final settlement.
Why do the laws restrict the surrender of leaves while in service?
Leaves are minimal in number, and no employee should be permitted to keep them so that they can encash them. However, at the same time, employees should be encouraged to avail of their leaves to maintain a work-life balance. If the leaves granted are over and above the mandatory amount as per the law, it will be considered an employee benefit, and the employer can have separate SOPs for encashment. The employer can specify that encashment will be based on basic salary alone.
Encashment of leaves as per the law
When it comes to the encashment of leaves as per the law, we should consider the wages as the base according to the law. My opinion is that the basic salary is just one component of the salary fixed by the employer, and it does not constitute the wages as per the contract of employment. In many cases, allowances like HRA and Conveyance are not compensatory allowances. Only compensatory allowances, such as those to cover certain costs like house rent, travel, meals, education, buying newspapers, and periodicals, are considered outside the scope of wages. Currently, these are part of the remuneration, and the total salary is subject to deduction when an employee takes unpaid leave.
Faulty compensation structuring
It is due to the faulty compensation structuring that these confusions arise. The industrial sense when the Factories Act or Shops Act was passed was different from the current industrial practice. In the past, wages would refer to basic salary and dearness allowance, where the latter was paid to account for the increasing cost of living, and the former represented the cost of labor. All other payments and contributions payable by the employer due to that employment, such as bonus, PF, ESI, gratuity, etc., were costs borne by the employer, and these were implied without the need to show them separately in the salary offer sheet. However, now it is not just the cost of labor but the total cost to the company. It includes the total cost of engaging an employee, statutory and other benefits, maximum incentives, or even the cost of awards or performance bonuses that may be earned by achieving certain goals, all of which are shown in the salary sheet. It is rarely referred to as a salary offer but as a CTC offer!