After the privatization of state-owned companies, new employers tend to adjust their labor force in order to reduce ongoing costs and increase the company's profit. In order to persuade the employees to accept voluntary retirement and leave the firm, employers may offer a reward to the workers who are eligible for voluntary retirement but are not eligible for mandatory retirement. The purpose of this paper is the calculation of minimum bonus of encouragement retirement and analyzing the amount of mentioned minimum bonuses in Iran and using this for a case study in Telecommunication Company of Iran. In this regard, we calculate the minimum bonus for voluntary retirement in two  game theory models that called "encouragement retirement with mandatory retirement age" and "encouragement retirement with maximum work experience." The calculations show that eight variables of mandatory retirement age, recruitment age, life expectancy, work experience, minimum work experience under a maximum rate of pension, wage, pension and expected rate of interest rate affect the amount of the bonus. In addition, we choose the model of “encouragement retirement with the mandatory retirement age” to apply a practical model in Iran. This practical model includes the effect of gender, tax exemption, and relief. The results show that in general one can't comment about comparing the mentioned minimum bonus for persuading to retirement only based on the gender. The existence of tax exemption and relief increases the mentioned minimum bonus Then encouragement retirement instruction of Telecommunication Company of Iran is analyzed in the shadow of the applied model for Iran. Analyzing the instruction indicates the selected model for persuading to retirement is improper. Additionally, these instructions neglect the effect of the influential factors such as mandatory retirement age, recruitment age and life expectancy non-deductible items of insurance premium and difference between hard and hazardous jobs with ordinary jobs.