N.Y.C. Admin. Code § 17-152: § 17-152 Validity of lien; grounds for challenge.

a. In any proceedings to enforce or discharge the lien, the validity of the lien shall not be subject to challenge based on:

(1) The lawfulness of the work done; or

(2) The propriety and accuracy of the items of expenses for which a lien is claimed, except as provided in this section.

b. No such challenge may be made except by (1) the owner of the property, or (2) a mortgagee or lienor whose mortgage or lien would, but for the provision of section 17-151, have priority over the department's lien.

c. With respect to any issue specified in subdivision a of this section the certificate of the department filed pursuant to section 17-153 shall be presumptive evidence of the facts stated therein.