In line with Regulation (EC) No 715/2009, it is necessary to establish a network code on harmonised transmission tariff structures for gas, and set out the Union-wide rules which have the objectives of contributing to market integration, enhancing security of supply and promoting the interconnection between gas networks.

A crucial step in reaching these objectives is to increase the transparency of transmission tariff structures and procedures towards setting them. Therefore, it is necessary to set out the requirements for publishing the information related to the determination of the revenues of transmission system operators and to the derivation of different transmission and non-transmission tariffs. These requirements should enable network users to understand better the tariffs set for both transmission services and non-transmission services, as well as how such tariffs have changed, are set and may change. Additionally, network users should be able to understand the costs underlying transmission tariffs and to forecast transmission tariffs to a reasonable extent. The transparency requirements set out in this Regulation further harmonise the rule laid down in point 3.1.2(a) of Annex I to Regulation (EC) No 715/2009.

After the introduction of the concept of the entry-exit system by Regulation (EC) No 715/2009, transmission costs are no longer directly associated to one specific route as entry and exit capacity can be contracted separately, and network users can have gas transported from any entry to any exit point. Under this framework, the transmission system operator decides the most efficient way of flowing gas through the system. Hence, in order to achieve and ensure a reasonable level of cost reflectivity and predictability in such a system, transmission tariffs need to be based on a reference price methodology using specific cost drivers. The guiding principles in order to apply a consistent and transparent reference price methodology should be set out. The obligation to consult on the proposed reference price methodology should be laid down. Where the proposed reference price methodology is other than the capacity weighted distance reference price methodology, the latter should serve as a counterfactual for comparison with the proposed reference price methodology.

In order to avoid double charging for transmission to and from storage facilities, this Regulation should set a minimum discount acknowledging the general contribution to system flexibility and security of supply of such infrastructure. Storage facilities with direct access to the transmission systems of two or more transmission system operators in directly connected entry-exit systems, or simultaneously to a transmission system and a distribution system allow for transporting gas between directly connected systems. Applying a discount at entry points from or exit points to storage facilities in cases where storage facilities are used to transport gas between directly connected systems would benefit these network users compared to other network users booking capacity products without a discount at interconnection points or using storage facilities to transport gas within the same system. This Regulation should introduce mechanisms to avoid such discrimination.

In order to promote security of supply, the granting of discounts should be considered for entry points from LNG facilities, and at entry points from and exit points to infrastructure developed with the purpose of ending the isolation of Member States in respect of their gas transmission systems.

Transmission system operators in certain entry-exit systems transport significantly more gas into other systems than for consumption into their own entry-exit system. Consequently, reference price methodologies should include safeguards required to shelter such captive customers from risks related to large transit flows.

In order to promote stability of transmission tariffs for network users, to foster financial stability and to avoid detrimental effects on the revenue and cash flow positions of transmission system operators, principles for revenue reconciliation should be set out.

In addition, rules should be set out on tariff principles for incremental capacity realised in a market-based manner according to the process set out in Articles 26 to 30 of Commission Regulation (EU) 2017/459. In case realisation of incremental capacity leads to a level of cross-subsidisation that cannot be justified, as captive costumers would be exposed to a large share of the volume risk, this Regulation should introduce mechanisms to alleviate such risks.

This Regulation should be applicable to the non-exempted part of major new infrastructures which have received an exemption pursuant to Article 36 of Directive 2009/73/EC of the European Parliament and of the Council from Article 41(6), (8) and (10) of that Directive. In cases where the specific nature of interconnectors has been acknowledged at European level by an exemption in accordance with Article 36 of Directive 2009/73/EC or by other means, national regulatory authorities should have the power to grant a derogation from requirements of this Regulation which would jeopardise the efficient operation of such interconnectors.

This Regulation should be without prejudice to application of Union and national competition rules, in particular the prohibitions of restrictive agreements (Article 101 of the Treaty on the Functioning of the European Union) and of abuse of a dominant position (Article 102 of the Treaty on the Functioning of the European Union). The harmonised transmission tariff structures put in place should be designed in such a way as to avoid foreclosure of downstream supply markets.

National regulatory authorities and transmission system operators should have regard to best practices and endeavours to harmonise processes for the implementation of this Regulation. Acting in accordance with Article 7 of Regulation (EC) No 713/2009 of the European Parliament and of the Council, the Agency for the Cooperation of Energy Regulators and the national regulatory authorities should ensure that rules on harmonised transmission tariff structures for gas are implemented across the Union in the most effective way.

The measures provided for in this Regulation are in accordance with the opinion of the Committee established in accordance with Article 51 of Directive 2009/73/EC,