LC number or identity is normally computer generated or in some banks the number is manually assigned by the issuing bank. It is a combination of alphabet and numeric characters subject to a maximum of 16 characters. The presence of this field is mandatory.
This number will be used as a reference number for payment, enquiry and amendment, if there is any which refers to that same LC. It carries important implications to the whole LC operations. There are cases where multiple LCs issued by the same issuing bank, at the request of the same buyer, addressed to the same seller, with the same amount and same currency. Therefore, the only way to identify which LC is to be paid, accepted or negotiated is by identifying the LC number.
Field 31C (Date of issue) on the other hand, signifies the date on which the LC is issued by the issuing bank. The undertaking to make payment by the issuing bank takes effect from this date. This field must contain 6 numeric characters only with no alphabet in the following manner, yy/mm/dd. For example, if the date is indicated as 070104, it is read as January 04th, 2007.
This date format is also applied to field 31D (Date and place of expiry) and field 44C (Latest date of shipment).