I think that is a very good question.  With some of our clients it is obvious, but there are some that we don't know.  In any case I had the idea to contact all of the major ones.  I think most title agencies can write for more than one underwriter and they certainly can apply to work with others at any time.  But it would help to know for sure who they are writing for.  If you are sent a commitment as part of an update request it will be there.