N.Y. Comp. Codes R. & Regs. tit. 11, § 161.10 – Policies subject to audit.

(a) An audit to determine final premium for policies under which the initial premium is based on an estimate of the insured's exposure base shall be conducted within 180 days after expiration of such policy, and may not be waived except in the following circumstances:
1. (1) the total annual premium attributable to the auditable exposure base is not reasonably expected to exceed $1,500;
2. (2) the policy requires notification to the insurer with the specific identification of any additional exposure units for which coverage is requested (i.e., motor vehicles); or
3. (3) the policy is a commercial umbrella for which the rate or premium is determined by the application of a factor to the rate or premium of an auditable underlying policy.
(b) The insurer shall, as soon as practicable following such audit, refund or credit the insured's account for any return premium due the insured, or bill and make a good faith effort to collect any additional premium due the company, as a result of the audit.
(c) If an insured fails to cooperate with the insurer in its attempt to conduct such audit, including failure to return any questionnaires or self-audit worksheets, the insurer shall nonrenew such insured upon completion of the current policy period, in accordance with the provisions of section 3426 of the Insurance Law, due to the insurer's inability to establish a proper premium for such insured.