An undertaking is financed primarily by two groups: the financiers, generally banks, and the suppliers of the undertaking. The extent to which these separate groups can take security is a policy choice made by the lawgiver. Currently these policy choices are made on a national level. Should that remain so, or should the choices be made on a different level? This contribution aims to provide an answer to that question by concentrating on the substantive legal political choices that are currently made by the national legislators, and assess whether harmonization, either by a top-down or bottom-up approach, would provide at least a minimal efficiency gain (similar to a ‘Pareto-improvement’) relative to the current situation. In particular, the extent of the security that can be taken is assessed. Does this include future assets, newly formed goods, and even the proceeds of the sale to sub-purchasers? The development of the law on security in The Netherlands, England & Wales and Belgium is assessed in light of these questions. Furthermore, various model laws aimed at the harmonization of this area of the law, such as Book IX DCFR and Article 9 UCC, are also taken into account. The authors come to the conclusion that the national policy choices in relation to the security available for a financier are very similar, whereas in relation to suppliers there appears to be a larger discrepancy. Therefore, they purport that a functional approach, on the basis of a model law, would be the preferred method of harmonization. In this way step-by-step harmonization can be achieved, starting with a security right for financiers, without upsetting the national system of ‘superpriorities’.