(b) In conformity with subsection (c) of section thirty-three hundred five of the federal unemployment tax act, the commissioner is authorized to transmit a copy of any return or report of a national banking association relative to the association's employees, their remuneration and services, to the comptroller of the currency and to request the said comptroller of the currency to cause an examination of the correctness of such return or report to be made at the time of the next succeeding examination of such association, and thereupon to transmit to the commissioner a complete statement of his findings respecting the accuracy of such returns or reports.

(c) This subdivision applies to national banking associations and any other federal instrumentalities which would be immune from contributions required under this article without authorization by subsection (b) of section thirty-three hundred five of the federal unemployment tax act. 5. Primary liability for contributions. Whenever one employer contracts with a second employer for any work which is part of the first employer's usual trade, occupation, profession or enterprise, the first employer shall be liable for any contributions otherwise payable by the second employer, based upon wages paid in respect to such work, unless the second employer is free to do business with anyone who may wish to contract with him. Contributions so paid by the first employer on behalf of the second employer shall be deemed paid by the second employer. If the first employer fails to pay, on the date prescribed by the commissioner, contributions due on wages paid by the second employer, the commissioner may collect such deficiency from the second employer.