As an organization, PF registration is compulsory if the employee strength exceeds 20 employees. 

As an employee of an organization which is registered for PF, it is compulsory if either of these conditions is true -

  1. The employee earns less than Rs 15,000 per month. 
  2. The employee has contributed to PF before through any past employer.

XPayroll will let you override the automatic PF deduction for employees earning less than Rs 15,000 (by explicitly opting out of PF from the Provident Fund, Professional Tax & ESI section of their profile), but do note that this is technically against regulations.