The bank can only waive insurance from the date insurance is no longer required.
However, if a LOMA is issued the borrower should get a full refund of the premium, but that is between them and their insurance agent.
I'm at another branch this week so I don't have the link to the document in the favorites on this PC but search FEMA's Web page using CANCELLATION/NULLIFICATION as the search term. Then look for:
19. Insurance No Longer Required by the
Mortgagee Because the Structure Has
Been Removed from the Special Flood
Hazard Area (SFHA) by Means of Letter
of Map Amendment (LOMA) or Letter of
Map Revision (LOMR). (TRRP reason 20)
You will find within that section the following:
. . . .the policy
can be canceled provided the lender
confirms in writing that the insurance is no
longer required because the property was
removed from the SFHA. A copy of the
LOMA or LOMR must accompany this
request. . . .
Type of Refund: Full
Years Eligible for Refund: Current year
and, if applicable, 1 prior year provided
no claim has been paid or is pending
during the policy year that is being
canceled
Cancellation Request: Must be received
during the policy year or within 6 months
of the policy expiration date
Documentation: Statement from mortgagee
that flood insurance is no longer
required because the property was
removed from the SFHA, and a copy of
the LOMA/LOMR
_________________________
The opinions expressed are mine and they are not to be taken as legal advice.