@kgudgel "But does anyone know what will happen to the employer if 8919 is filed with code H?  Is it the same as when the SS-8 is filed (that the IRS is going to go after the firm anyways). "

Since the 8919 doesn't require the employer's address (and allows "unknown" for EIN), probably not much, in most cases.  Like all audit programs, IRS may pull a sample of higher-amount 8919s to track down companies that may be evading payroll taxes.  That would require Congress to appropriate money, and many in the legislative branch don't think it would be productive.  Also, if employers have to pay taxes it means less money for political contributions.