The L/C needs to be completed and send to our bank before production can start. I do not know what kind of L / C you have been making but the normal L / C is always opened right away when placing the order, and specified in the L/C is the latest date of shipment from the factory that the L/C allows in order for it to be valid. You do not need any invoice or other documents at this time for the opening of the L/C trough your bank.