When shipment delays incur detention charges that need to be recovered from a customer, the question arises whether to issue a debit note or a formal invoice. The consensus leans towards issuing an invoice for these charges, even if it's not your primary business. This approach is recommended as detention charges are not considered part of a composite supply or additional consideration for the main service.
31 March 2020
Due to delay in shipment we need to pay some amount as detention charges and as per term , we need to recover the same from the customer .
02 April 2020
In my opinion it is neither a composite supply nor and additional consideration and therefore it is appropriate to issue an Invoice for detention charges and charge GST thought it is not your main line of supply.