Subd. 1. Whenever an insurance certificate is required by this chapter, the applicant shall file with the city administrative offices a certificate of insurance showing:
A. That the limits are at least as high as required;
B. That coverage is effective for at least the license term approved; and
C. That the insurance will not be cancelled or terminated without a 30-day written notice served upon the city administrative offices.
Subd. 2. Cancellation or termination of such coverage shall be grounds for license revocation.
(`80 Code, § 5.13)