The business lookup ID used during the Constituent batch update should be used to pull in additional information into the batch for the business. IE. Business name, address, phone number. You may experience the business Lookup ID not functioning by not pulling any of the business information from the constituent's record.
We're currently evaluating this issue for a fix in a future patch or service pack.
Steps to Duplicate
1. Create a Constituent update batch template 2. Create a CSV file with the business Lookup ID field, business name, business address, business phone 3. Use auto-map to map to the coordinating fields. 4. Process the import 5. Check the completed batch to see if the business Lookup ID imported any of the business information. The business Lookup ID did not import any business information (business name, address, or phone) as expected.