N.Y. Comp. Codes R. & Regs. tit. 12, § 300.17
(a) An attorney or licensed representative shall file a notice of retainer and appearance, and, when appropriate, a notice of substitution, in the format prescribed by the chair, immediately upon being retained. The attorney or licensed representative shall also transmit a copy of such notice to the insurance carrier, self-insured or other representative of the employer at the time of filing.
(2) An attorney or licensed representative may withdraw from representation of a claimant when:
(b)
(c) No fee shall be approved or fixed, in accordance with subdivision (f) of this section, for the services of any such attorney or licensed representative who has failed or neglected to serve and file the required notice of retainer and appearance, the required notice of substitution, or obtained approval of a withdrawal of representation as required in paragraph (b)(2) of this section.
(d)
In the representation of a claimant before the board or a Workers' Compensation Law judge in any case: