You need to include ESI on 15500.
Overtime Allowance
In the case of the employer, as and when the employer finds the need to have work done expeditiously, in addition to the normal work during the course of the working hours, the employer offers the employee the option to do overtime work after the working hours. When an employee does overtime work, it implies acceptance of the same, thereby establishing an implied contract between the employer and the employee. Both the remuneration received during the working hours and overtime constitute a composite wage, making it a wage within the meaning of Sec.2(22) of the ESI Act. Therefore, contributions are payable on the overtime allowance. However, overtime allowances will only be considered as wages for the purpose of contribution calculation and not for determining the coverage of the employee under the Scheme.
This viewpoint was also upheld by the Supreme Court in its judgment delivered on 6.11.96 in the case of Indian Drugs & Pharmaceuticals Ltd. Vs. ESIC, in Civil Appeal No.2777 of 1980.
(Old instructions issued via memo No.3-1(2)/3(1)/68 dated 31.5.68).