Check your Letter of Credit form. Yours may have standard "auto renewable" working. Ours is the other way around. We have an expiration date (usually one year) and then we add "auto renewal" wording if the officer so chooses, because different situations warrant different maturities. If you know that the customer will need a new L/C every year, it is less labor intensive for you to have the auto renewal. If the L/C is a one-shot deal, take the auto renewal wording out, so there is no chance of the L/C "rolling" over for another year before you get the letter out saying you will not be renewing it.
_________________________
Just working here until I get my letter from Hogwarts.