How to Configure MassLOOP for Person Accounts

Problem:

The MassLOOP button requires you to specify a Contact Id for the &contactfield=  parameter but Person Accounts leverage Account Ids rather than Contact Ids.

Solution:

If you are generating the document from the Person Account record, use PersonContactId .
Example: &contactfield=PersonContactId

If you are generating the document from a custom object, reference the Person Account look-up field before PersonContactId .
Example: &contactid=customfield__r.PersonContactId