Answer:
The regulations have not yet been written by the CFPB that address the requirement for the number to be on "all loan documents." So far, the only requirements other that those in 12 CFR Part 1007 seem to be from participants in the secondary market (Fannie and Freddie and their ilk). Unless and until the CFPB rule is issued in final form and is effective, I think you can get by quite nicely without recording the MLO's number on the application.
First published on BankersOnline.com 10/1/12