Cross-border transactions and resultant legal proceedings often cause problems. One major problem is knowing which law should govern the transaction and any legal proceedings. Cross-border insolvencies in the EU are subject to the European Regulation on Insolvency Proceedings (EIR) but this legislation does not determine which substantive insolvency law rules apply in a given insolvency. There are many differences in the insolvency rules applicable in the various EU Member States and this has caused concern in relation to the avoidance of transactions entered into by an insolvent prior to the opening of insolvency proceedings. In light of this, the paper examines options to address divergence between national avoidance rules. One option, harmonization, is analysed as well as its possible benefits and drawbacks.