An invoice or a GST bill is a list of goods sent or services provided, along with the amount due for payment.
GST invoice should be issued when payment for goods or services is received or reasonably assured or if the goods or services have been supplied. If goods or services are supplied and payment is not received, then invoice must be issued within 30 days - irrespective of the status of the receivable
It is important to note that the supplier becomes liable for remittance of GST to the government on the issuance of tax invoice, even if payment is not received from the customer. Hence, if payment is not reasonably assured, and goods or services have not been delivered, an estimate can be issued by the supplier
All GST invoices must be prepared in triplicate in case of a supply of goods. The original copy should be marked as ORIGINAL FOR RECIPIENT. The duplicate copy should be marked as DUPLICATE FOR TRANSPORTER, and the triplicate copy should be marked as TRIPLICATE FOR SUPPLIER.
In case of a supply of services, the invoice should be prepared in duplicate. The original copy should be marked as ORIGINAL FOR RECIPIENT, and the duplicate copy should be marked as DUPLICATE FOR SUPPLIER.