(a) In general. If more than the correct amount of the employer's contribution is paid with respect to any compensation and the overpayment may not be adjusted in accordance with § 345.118 of this part, the amount of the overpayment shall be refunded in accordance with this section.

(b) When permitted. A claim for refund may be made only when the overpayment cannot be adjusted in accordance with the procedure set forth in § 345.118.

(c) Form of claim. A claim for refund shall be directed to the Chief Financial Officer and shall set forth all grounds in detail and all facts alleged in support of the claim, including the amount and date of each payment to the Board of the contribution to the Board, and the period covered by the contribution report on which such contribution was reported.

(d) Claim by fiduciary. If an executor, administrator, guardian, trustee, or receiver files a claim for refund, evidence to establish the legal authority of the fiduciary shall be annexed to the claim filed by such fiduciary under this section.

(e) Time limit. No refund shall be allowed after the expiration of three years from the time the contribution report was required to be filed or two years from the time the contribution was paid, whichever of such periods expires the later, or if no contribution report was filed, two years from the time the contribution was paid.

(f) Interest. Interest shall be payable on any contribution refunded at the overpayment rate provided for in section 6621 of the Internal Revenue Code of 1986 from the date of the overpayment to a date preceding the date of the refund check by not more than 30 days.

(g) Refunds reduced by underpayments. Any overpayment claimed or a refund under this section shall be reduced by the amount of any amount of any contributions previously assessed under § 345.120 of this part, which has not already been collected.