(a)
General rule
There is hereby imposed on every rail employer for each calendar month an excise tax, with respect to having individuals in his employ, equal to 4 percent of the total rail wages paid by him during such month.
(c)
Termination if loans to railroad unemployment fund repaid
The tax imposed by this section shall not apply to rail wages paid on or after the 1st day of any calendar month if, as of such 1st day, there is—
(1)
no balance of transfers made before October 1, 1985, to the railroad unemployment insurance account under section 10(d) of the Railroad Unemployment Insurance Act, and
(2)
no unpaid interest on such transfers.