(a) The earned commission which shall be paid to any property or casualty insurance agent or broker duly licensed by a state insurance regulatory authority, with respect to each policy or renewal the agent duly procures on behalf of the insured, in connection with policies of flood insurance placed with the NFIP at the offices of its servicing agent, but not with respect to policies of flood insurance issued pursuant to Subpart C of this part, shall not be less than $10 and is computed as follows:

(1) In the case of a new or renewal policy, the following commissions shall apply based on the total premiums paid for the policy term:

(2) In the case of mid-term increases in amounts of insurance added by endorsements, the following commissions shall apply based on the total premiums paid for the increased amounts of insurance:

(b) Any refunds of premiums authorized under this subchapter shall not affect a previously earned commission; and no agent shall be required to return that earned commission, unless the refund is made to establish a common policy term anniversary date with other insurance providing coverage against loss by other perils in which case a return of commission will be required by the agent on a pro rata basis. In such cases, the policy shall be immediately rewritten for a new term with the same amount(s) of coverage and with premium calculated at the then current rate and, as to return premium, returned, pro rata, to the insured based on the former policy's premium rate.