Article 163 defines the Chairman's authority regarding payment deferrals. If a postponement request is submitted on time, the Chairman will issue a decision to either reject it or postpone the whole or part of the tax. As a condition for granting the postponement, the Chairman has the power to demand that the taxpayer provide bank guarantees. This ensures that while the taxpayer is granted temporary relief from immediate payment, the state's eventual recovery of the tax is secured against the risk of the taxpayer's future insolvency or non-compliance.