Credit note reduces supplier tax liability by amending the original invoice value under GST, enabling adjustments for returns. A credit note is a document notifying that a buyer's account is credited for errors, returns or allowances and, under GST, permits amendment of the original tax invoice value so the supplier can reduce taxable liability in returns without a refund; as valuable consideration it may represent the price for goods transferred (for example spare parts) and be reflected as an accounting liability for the supplier.