Government carriers such as Medicare, Medicaid, Railroad Medicare, federal employees, and Tricare require the providers original signature in Block 31 of the form when sent by paper.
Commercial insurance companies may allow SOF or Signature On File in block 31.
When we get a new provider, we have him/her sign a letter that basically states:
I hereby authorize the following ABC Billing Company staff members to sign paper claim forms submitted on my behalf. A copy of this letter acts the same as the original document.
It listed the names of the staff members. A copy is on file in the office safe and in our bank safe deposit box. The first claims we send for this provider, on paper, have a photocopy of the letter attached with the claims, along with a W-9 tax form. We only do this as a preventive measure to keep claims payments from being delayed.