EPF - irrespective of days being served by employees under contract, a contractor should remit contribution for whole month

Seeking guidance about remitting epf contributions. One of my client Hr says irrespective of days being served by employees under contract, a contractor should remit contribution for whole month. I said its done at actuals as per attendance .but he said you submit any circular if so available. Please help.

a contractor depute his employees to any establishment for few days, but the employee remains employee with contractor for whole month
if the contractor did not availed the services of the employee for whole month then it would be clearly reflected in ECR as NCP days for balance of remaining days, because the employee remains employee to the contractor for whole month, irrelevant of the contract days
i.e if the contractor deputed any employee to any establishment for mere 10 days then , balance 21 days of august 2018 would be NCP (non contributory period)