https://codes.findlaw.com/ny/insurance- ... sect-1111/Whenever by any law of this state any policy or contract of insurance is required, or is acceptable in lieu of any other requirement imposed by such law, the superintendent may, upon written request containing such information as he deems necessary, issue to any person a certificate of qualification, stating the qualification of any insurer authorized to do such business in this state if he finds that, as shown by the insurer's last filed annual statement or last filed report on examination, whichever is later, the insurer is solvent, responsible and otherwise qualified to make policies or contracts of the kind required.
Also NY CPLR § 2506 "Exception to surety: allowance where no exception taken."
https://law.justia.com/codes/new-york/2 ... e-25/2506/(a) Exception to surety. If a certificate of qualification issued pursuant to subsections (b), (c) and (d) of section one thousand one hundred eleven of the insurance law is not filed with the undertaking, a party may except to the sufficiency of a surety by a written notice of exception served upon the adverse party within ten days after receipt of a copy of the undertaking.
And CPLR § 2507 "Justification of surety."
https://law.justia.com/codes/new-york/2 ... e-25/2507/(a) Motion to justify. Within ten days after service of notice of exception, the surety excepted to or the person upon whose behalf the undertaking was given shall move to justify, upon notice to the adverse party and to the sheriff if he was served with the undertaking. The surety shall be present upon the hearing of such motion to be examined under oath. If the court find the surety sufficient, it shall make an appropriate indorsement on the undertaking. A certificate of qualification issued pursuant to subsections (b), (c) and (d) of section one thousand one hundred eleven of the insurance law shall be accepted in lieu of a justification.
(b) Failure to justify. If a motion to justify is not made within ten days after the notice of exception is served, the undertaking shall then be without effect, except as provided in this subdivision. Unless otherwise provided by order of court, a surety on an undertaking excepted to and not justified shall remain liable until a new undertaking is given and allowed, but the original undertaking shall be otherwise without effect.
I also took a look at the appeal undertaking filed by Federal Insurance Company (Chubb subsidiary) in Carroll v. Trump, and I see that it contains the supporting documents missing from the Knight Specialty Insurance undertaking, viz, a certificate of solvency under Insurance Law § 1111 issued to the Federal Insurance Company by the NYS Department of Financial Services, with a statement of assets, liabilities and surplus.
https://storage.courtlistener.com/recap ... 29.1_1.pdf
So, whether or not Knight Specialty Insurance is authorized by the NYS Department of Financial Services to write surety bonds, the bond filed does appear to be defective on its face for lack of a certificate of solvency aka certificate of qualification.