Would it be considered a federal crime to call the IRS and impersonate a plan official to tell the IRS that they are mistakenly threatening the sponsor with adverse consequences because no 5500 was filed for a year in which the plan did not exist ? If so, then either the plan sponsor has to actually contact the IRS themselves or provide the TPA a PoA to authorize them to do it for them. If not, since no confidential information would be communicated in either direction, why not do that? Just saying.