The legal framework for the gas storage market is characterised particularly by the 3rd European internal energy market package that came into force early September 2009. The package comprises several directives and regulations. The directive concerning common rules for the internal market in natural gas contains guidelines for unbundling storage system operators, regulating storage access, and the responsibilities of the regulatory authorities. The Regulation on the conditions for access to natural gas transmission networks now gives statutory character to the Guidelines for Good TPA Practice for Storage System Operators (GGPSSO) that previously had no binding effect.

The rules of the 3rd European internal energy market package, relating to the storage of natural gas, particularly aims at securing the independency of storage system operators, increasing the transparency of the capacities offered, and, finally, improving third party access to storage systems.