This paper discusses the current Czech and European legal framework applicable to the adjustment to the taxable amount with respect to claims partially cancelled due to the insolvency of the customer resolved by reorganisation. The partial cancellation, according to the authors, serves as grounds to adjust a taxable amount under the EU VAT Directive. The supplier is entitled to issue a corrective invoice and claim a refund of a proportion of the VAT paid with respect to the delivery of goods or services to an insolvent debtor. However, such practice is not yet followed by the Czech tax authorities who do not allow for a reduction of a taxable amount in reorganisation and only allow such reductions in the case of bankruptcy liquidation. The paper argues that this approach is not compatible with European law. Moreover, such a different treatment of VAT payers in bankruptcy liquidation (resulting in higher satisfaction of VAT taxpayers as creditors) puts reorganisation at a considerable disadvantage and is contrary to the basic principles of insolvency law. Finally, the paper argues that the corresponding claim of the tax authority resulting from the VAT base adjustment constitutes a standard pre-insolvency claim and should not be preferred in the insolvency proceedings under Czech law.