An 4010X098A1 (claim) file gets created with a billing loop that looks like:

NM1*85*2*Name here*****24*111111111~
N3*address1*address2~
N4*city*st*zip~
REF*G2*2222222~

The claim goes through fine. I send over a 4010X093A1 (status) request for the claim. It allows for only one identifier for the provider:

NM1*1P*2*Name here*****SV*2222222~

The carrier doesn't want the carrier specific ID that we sent, they want the tax ID:

NM1*1P*2*Name here*****FI*111111111~

It is difficult to determine what the insurance carrier wants because they can make their own rules about what they want in the segment.

I suggest making the loops (aside the from the subscriber specific loops) the same across all transactions. The vendor should be able to create the same envelope, receiver loop, submitter loop, billing loop, etc. regardless of what transaction is being sent. This way the carrier can't say that they can't take a number here or there for a certain transaction, because they would be getting all the same information as was sent for the claim.