Held, it was conceivable that a defendant in a European order for payment procedure may have been prevented from lodging a statement of opposition due to extraordinary circumstances linked to the COVID‑19 pandemic and, in such a situation, he was entitled to apply for a review of that order. Since the EU legislature intended to limit the review procedure to exceptional circumstances, article 20(1)(b) of Regulation (EC) No 1896/2006 had to be interpreted strictly and was not intended to apply to extraordinary circumstances of a systemic nature, which generally affected the operation and administration of the courts. While articles 16 and 20 of Regulation laid down the defendant’s right to lodge a statement of opposition to an order, neither of those articles nor any other provision of that Regulation governed other aspects, such as the basis for interruption or suspension of the time period while it was running. Consequently, and in accordance with article 26 of the Regulation, member states were entitled to supplement the procedural aspects which were not dealt with in articles 16 and 20. In the absence of EU rules on the matter, it was for the national legal order of each member state to establish them, provided that those procedural rules were not less favourable than those governing similar domestic situations (principle of equivalence) and that they did not make it impossible or excessively difficult to exercise the rights conferred by EU law (principle of effectiveness). The Austrian Law on COVID‑19 applied without distinction to all procedural periods in civil cases, irrespective of the legal basis of the action in question. Accordingly, subject to verification by the referring court, the legislation appeared to ensure equal treatment for orders for payment procedures under national law and similar procedures under the Regulation and satisfied the principle of equivalence. National legislation which had the effect of interrupting the period laid down in article 16(2) for opposing an order complied with the principle of effectiveness where it appeared justified by ensuring observance of the defendant’s rights of defence without making it excessively difficult to recover the claims in question speedily and effectively. In the present case, the national legislation simply provided for an interruption for approximately five weeks which corresponded to the period during which judicial activities were severely disrupted on account of the lockdown imposed due to the COVID‑19 pandemic. Accordingly, articles 16, 20 and 26 of Regulation No 1896/2006 did not preclude the application of national legislation to the 30-day time limit laid down by article 16(2) for the defendant to lodge a statement of opposition to a European order for payment, that legislation having been adopted when the COVID‑19 pandemic arose and which interrupted the procedural periods in civil matters for approximately five weeks (judgment, paras 31, 32–33, 35, 37–41, operative part).