Where a person pays to the Commissioners an amount by way of excise duty which is not due to them, the Commissioners are liable to repay that amount.

The Commissioners shall not be required to make any such repayment unless a claim is made to them in such form, and supported by such documentary evidence, as may be prescribed by them by regulations; and regulations under this subsection may make different provision for different cases.

It is a defence to a claim for repayment that the repayment would unjustly enrich the claimant.

The Commissioners shall not be liable, on a claim made under this section, to repay any amount paid to them more than F44 years before the making of the claim.

Except as provided by this section the Commissioners are not liable to repay an amount paid to them by way of excise duty by reason of the fact that it was not due to them.