Dear Aditi,
Thank you for the good question.
A joining bonus can be given for several reasons, sometimes to attract candidates from different locations. A joining bonus is a sum of money paid to a new employee by a company as an incentive to join that company. They are often given as a way of making a compensation package more attractive to the employee.
Companies offer joining bonuses as the demand for a skilled workforce is high. There are crucial positions that need to be filled quickly, and companies cannot afford to wait to onboard people.
The main reasons for offering a joining bonus are to ensure that the company acquires the right talent at the right time. Joining bonuses are estimated to be in the range of 10 to 20 percent of the employee's Cost to Company (CTC).
The trend of offering joining bonuses is more prevalent in sectors such as BFSI (Banking, Financial Services, and Insurance), IT, services, power, energy, and infrastructure.
I have noticed that several companies offer joining bonuses to prospective employees to join early (or shall I say "immediately").
I hope this clears up your doubt.