Regulation 46C

in any prescribed accounting period (called in this Part the subject accounting period), a reduction is made in the value of any taxable supply of a registered (Seventh Schedule — pay only) person (whether the taxable supply took place in the subject accounting period or any earlier prescribed accounting period), including a reduction resulting from the person issuing a credit note in the subject accounting period in respect of the supply; and

the registered (Seventh Schedule — pay only) person has reimbursed the customer (whether by way of payment made or set-off effected against any moneys owed by the customer to the registered (Seventh Schedule — pay only) person) for the reduction in tax for the relevant supply,but not where the reduction in tax and reimbursement is in relation to any tax on the relevant supply overpaid or erroneously paid by the registered (Seventh Schedule — pay only) person to the Comptroller as a result of the value originally ascribed by the registered (Seventh Schedule — pay only) person to the relevant supply.