Urgent! interest on msme

Hi

Interest on Micro, Small and Medium enterprises (MSME) to be provided in books for delayed payments beyond 45 days (Max credit period as per MSMED Act 2006).

I come across the situation, where the company is provided the interest for MSME creditors where ever the payment is made beyond 45 days. Since the PO terms is 60 days, all payments made to supplier exceeds the limit of 45 days. Last 3 years they provided the interest, the accumulation is about 60 lakhs. The suppliers is also not demanding for interest, since it is before the due date for them. 

In this context, I have a questions 

1. If the PO terms says 60 days as the credit period, whether interest should be provided in books?

2. The outstanding as on year end is NIL to the MSME creditors, still interest to be provided?

3. If interest is provided in books, when it should be paid to the creditors? Is there any time limit for payment.

4. The contention of the company is not going to pay to the supplier as per PO terms.

Please advice.

Thanks