Once you've bought or sold an item, you cannot change the number of items in the item's buying and selling units. If you want to change these units of measure for an item you've been using for awhile, you'll have to create a new item record and transfer the items from the old record to the new record.
After you've created the new item record with the new units of measure, you can use the Transfer Inventory window to transfer the items from the old item record to the new one. For example, assume you been buying an item in 12-can cases and you want to track purchases by individual cans. In this instance, enter an inventory transfer that brings the number of cases on hand for the old item number to zero and increases the quantity on hand for the new item number by the number of individual cans in the cases.
This tip applies to:
Item Information window -- Profile view
Item Information window -- Buying Details view
Item Information window -- Selling Details view