1. Introduction

Electric-vehicle (EV) charging network interoperability refers to the ability of different charging networks, charging operators, vehicle manufacturers, mobility-service providers, payment systems, and software platforms to interact seamlessly. Interoperability can concern:

• Technical interoperability — whether an EV can physically connect to a charger;
• Communications interoperability — whether the vehicle, charger and network-management system can exchange data;
• Roaming interoperability — whether a driver registered with one charging provider can use another provider's network;
• Payment interoperability — whether users can pay without maintaining multiple accounts or applications;
• Data interoperability — whether charging, pricing, availability and authentication data can move between systems;
• Protocol interoperability — compatibility with standards such as OCPP, OCPI, ISO 15118 and related communication standards.

From a competition-law perspective, interoperability is important because charging networks can develop significant network effects, switching costs and ecosystem lock-in. A dominant charging operator or vertically integrated EV manufacturer may have incentives to restrict interoperability and thereby disadvantage rival charging operators.

The principal legal question is therefore:

When does a privately controlled technical or commercial interface become a competition-law problem because its restriction forecloses competing EV-charging services?

There is no single EU or national judgment specifically establishing a comprehensive "EV charging interoperability doctrine." Instead, the legal framework is constructed from essential-facilities, refusal-to-deal, interoperability, standard-setting, tying, discrimination, data-access and digital-platform cases.

2. Why Interoperability Matters in EV Charging

An EV charging ecosystem involves several interconnected layers:

EV manufacturer → vehicle software → charging hardware → charging-network operator → roaming platform → payment provider → electricity supplier → navigation/data platform

A failure at any layer can prevent effective competition.

Example

Suppose Network A controls 60% of fast-charging stations along major highways and refuses to permit Network B's customers to access its chargers through roaming.

Network B may technically operate its own stations, but its customers cannot obtain nationwide coverage.

The restriction could therefore produce:

• customer lock-in;
• reduced network coverage;
• higher prices;
• duplication of infrastructure;
• reduced investment;
• reduced consumer choice;
• exclusion of smaller charging operators.

3. Main Forms of EV Charging Interoperability

A. Hardware Interoperability

The first issue is whether the EV physically connects to the charging station.

Important variables include:

• connector standards;
• charging power;
• voltage;
• current;
• communication protocols;
• vehicle compatibility;
• safety systems.

A proprietary connector can create a competitive advantage if it prevents rival charging infrastructure from serving a large vehicle population.

B. Software and Communication Interoperability

Charging infrastructure depends heavily upon software.

A charger may communicate with a charging-network management system through protocols such as OCPP.

Competition concerns may arise where an operator:

• refuses to disclose technical interfaces;
• deliberately uses proprietary protocols;
• prevents third-party software integration;
• limits access to charging-status information;
• makes switching between network-management systems difficult.

C. Roaming Interoperability

Roaming permits a customer of one charging-service provider to use another network.

For example:

Customer of Network A → roaming platform → Network B charger.

Without roaming, customers may need:

• multiple applications;
• multiple contracts;
• multiple payment accounts;
• multiple authentication systems.

This can substantially increase switching costs.

D. Payment Interoperability

Payment fragmentation can itself become a barrier.

A charging operator may require:

• proprietary applications;
• compulsory subscriptions;
• exclusive payment arrangements;
• pre-registration;
• closed digital wallets.

Competition authorities may examine whether such requirements unnecessarily exclude competing mobility-service providers.

4. Competition-Law Issues

4.1 Refusal to Deal

The most obvious theory is abuse of dominance through refusal to provide interoperability.

Article 102 TFEU may become relevant where:

1. the charging infrastructure constitutes an important input;
2. the operator possesses substantial market power;
3. interoperability is indispensable or highly important;
4. refusal forecloses effective competition;
5. there is insufficient objective justification.

The classic starting point is United Brands v Commission, which established important principles concerning access to an undertaking's facilities and discriminatory conduct.

5. Case Law

Case 1 — Commercial Solvents Corp. v Commission

Cases: Commercial Solvents Corporation and Others v Commission, Joined Cases 6/73 and 7/73.

Principle

The Court of Justice recognised that a dominant undertaking controlling an essential input could abuse its dominant position by refusing supplies to downstream competitors where the conduct was capable of eliminating competition.

Relevance to EV charging

The analogy is powerful where a charging-network operator controls infrastructure or an essential upstream service.

For example:

Charging-network operator → controls critical charging access → competes downstream in EV mobility services.

If the operator restricts access to disadvantage competing mobility providers, Article 102 concerns may arise.

Key lesson

Control over an important input cannot automatically be used to eliminate downstream competition.

6. Case 2 — United Brands v Commission

Case: United Brands Company and United Brands Continentaal BV v Commission, Case 27/76.

Principle

The Court examined dominance, market access and discriminatory conduct in a market where the undertaking had substantial commercial power.

The judgment is particularly relevant to:

• market definition;
• dominance;
• exclusionary conduct;
• discrimination.

EV charging relevance

A charging operator with a large geographic network could potentially possess substantial market power, particularly in:

• motorway fast charging;
• urban fast charging;
• fleet charging;
• destination charging.

If access conditions differ systematically between affiliated and independent mobility providers, discriminatory-access theories may arise.

7. Case 3 — Oscar Bronner v Mediaprint

Case: Oscar Bronner GmbH & Co. KG v Mediaprint Zeitungs und Zeitschriftenverlag GmbH & Co. KG, Case C-7/97.

Principle

This is one of the most important cases concerning essential facilities.

The Court established a demanding test for forcing a dominant undertaking to provide access to infrastructure.

Among the central considerations were:

1. whether access is indispensable;
2. whether there is no actual or potential substitute;
3. whether duplication is impossible or economically unreasonable;
4. whether refusal eliminates effective competition.

EV charging relevance

Suppose an EV charging network controls virtually all ultra-fast chargers at strategically important motorway locations.

A rival network might argue:

"We cannot compete effectively unless we can access this network."

Bronner indicates that mere usefulness is not enough.

The infrastructure must satisfy a high threshold of indispensability.

Key lesson

Not every important charging network becomes an essential facility.

8. Case 4 — IMS Health v NDC Health

Case: IMS Health GmbH & Co. OHG v NDC Health GmbH & Co. KG, Joined Cases C-418/01.

Principle

The Court developed the exceptional circumstances surrounding compulsory access to protected infrastructure or intellectual property.

The case emphasised factors including:

• indispensability;
• elimination of competition;
• prevention of a new product or service;
• absence of objective justification.

EV charging relevance

This becomes particularly important where interoperability depends upon:

• proprietary charging software;
• APIs;
• patented communication technology;
• proprietary authentication systems;
• charging-management databases.

A charging operator cannot automatically be compelled to license every proprietary technology merely because competitors would benefit.

9. Case 5 — Microsoft v Commission

Case: Microsoft Corp. v Commission, Case T-201/04.

Principle

Microsoft is one of the most important interoperability cases in EU competition law.

The Commission and General Court addressed Microsoft's refusal to provide interoperability information necessary for competing work-group server products.

The case demonstrated that interoperability information can itself have competitive significance.

EV charging relevance

The analogy is especially strong for:

• APIs;
• communication protocols;
• charger-management interfaces;
• authentication systems;
• data interfaces.

If a dominant charging platform deliberately withholds technical information necessary for rival services to interoperate, the Microsoft reasoning may become relevant.

Key lesson

Technical interoperability can be a competitive input, not merely an engineering preference.

10. Case 6 — Slovak Telekom v Commission

Case: Slovak Telekom a.s. v European Commission, Joined Cases C-165/19 P and C-166/19 P.

Principle

The Court dealt with exclusionary conduct involving access to infrastructure and the relationship between competition-law refusal-to-deal principles and regulated access obligations.

The case is important because it illustrates how infrastructure access and regulatory obligations can interact with Article 102 TFEU.

EV charging relevance

The EV sector increasingly combines:

• private infrastructure;
• public infrastructure;
• regulated electricity networks;
• public subsidies;
• municipal concessions;
• highway concessions.

Where charging infrastructure is subject to regulatory access obligations, a competition authority may have stronger grounds for scrutinising discriminatory access.

11. Case 7 — Bronner and the Essential-Facilities Threshold in EV Charging

Although Bronner is the principal case, the later jurisprudence must also be understood through cases such as Slovak Telekom and Deutsche Telekom.

The important distinction is between:

Ordinary refusal to deal

A dominant undertaking generally retains commercial freedom regarding its business partners.

Essential-facility situation

Compulsory access becomes much more plausible where refusal concerns infrastructure that competitors genuinely cannot replicate or replace.

This distinction prevents competition law from becoming a general system of compulsory sharing.

12. Case 8 — Deutsche Telekom v Commission

Case: Deutsche Telekom AG v Commission, Case C-280/08 P.

Principle

The Court considered exclusionary conduct involving access pricing and downstream competition.

The judgment is particularly important for infrastructure industries because a vertically integrated operator can potentially use control over upstream infrastructure to disadvantage downstream competitors.

EV charging relevance

Consider:

Charging infrastructure operator + charging-service provider + mobility application

If the operator supplies infrastructure to independent mobility providers while simultaneously competing with them downstream, competition authorities may examine:

• discriminatory access;
• margin squeeze;
• pricing discrimination;
• foreclosure.

13. Case 9 — Google Shopping

Case: Google and Alphabet v Commission, Case T-612/17.

Principle

The General Court upheld the Commission's finding concerning Google's treatment of comparison-shopping services and the use of its dominant general-search infrastructure.

The case illustrates how platform control combined with discriminatory treatment can produce foreclosure effects.

EV charging relevance

The analogy becomes important for charging platforms that control:

• charging-location discovery;
• navigation;
• charger availability data;
• payment interfaces;
• ranking systems.

If a dominant platform systematically privileges its affiliated charging services over independent operators, competition concerns may arise.

14. Case 10 — Google Android

Case: Google LLC and Alphabet Inc. v Commission, Case T-604/18.

Principle

The case concerned Google's contractual and ecosystem restrictions surrounding Android.

Important competition concepts include:

• ecosystem power;
• tying;
• contractual restrictions;
• default arrangements;
• leveraging market power into adjacent markets.

EV charging relevance

An EV manufacturer could potentially control:

vehicle → operating system → navigation → charging application → payment → preferred charging network.

Exclusive or preferential integration may become problematic where it forecloses rival charging services.

15. Interoperability and Standard-Setting

Interoperability frequently depends upon technical standards.

Examples include:

• OCPP;
• OCPI;
• ISO 15118;
• charging connector standards;
• smart-charging protocols;
• Plug & Charge authentication.

Standard-setting can generate enormous competitive benefits because it allows multiple suppliers to operate within a common ecosystem.

However, standard-setting itself can create competition problems.

16. Standard-Setting Competition Concerns

A dominant participant might attempt to:

1. exclude rival technologies;
2. manipulate the standard-setting process;
3. impose discriminatory technical requirements;
4. conceal commercially important information;
5. use standards to exclude competing suppliers;
6. require unnecessarily restrictive licensing conditions.

The legal analysis can involve Article 101 TFEU, particularly where competing undertakings collectively establish standards.

17. Huawei v ZTE

Case: Huawei Technologies Co. Ltd v ZTE Corp., Case C-170/13.

Principle

The Court addressed enforcement of standard-essential patents and the relationship between:

• standardisation;
• FRAND licensing;
• intellectual property rights;
• dominance;
• competition law.

EV charging relevance

Future EV charging standards may contain patents essential to:

• wireless charging;
• communication protocols;
• authentication;
• smart charging;
• vehicle-to-grid functionality.

If a patented technology becomes essential to interoperability, FRAND-related competition questions can arise.

18. Rambus

Case: Rambus Inc. v European Commission, Case T-148/10.

Principle

The case concerned alleged conduct surrounding standard-setting and disclosure of intellectual-property rights.

EV charging relevance

A charging technology provider participating in standard-setting could potentially obtain strategic advantages if it:

• conceals relevant patents;
• waits until competitors become locked into a standard;
• subsequently demands excessive licensing terms.

Thus, standard-setting neutrality is central to interoperability competition.

19. Network Effects

EV charging is particularly susceptible to network effects.

A larger charging network attracts:

• more EV drivers;
• more fleet operators;
• more roaming partners;
• more payment providers.

Those users increase the network's attractiveness, which attracts still more participants.

This can produce:

Scale → users → data → investment → more chargers → greater scale

The resulting feedback loop can make market entry increasingly difficult.

20. Data Interoperability

Charging networks generate valuable data concerning:

• charger availability;
• location;
• charging speed;
• utilisation;
• pricing;
• congestion;
• charging history;
• vehicle identification;
• energy consumption.

A dominant operator may have incentives to restrict access to this data.

Competition questions may therefore arise regarding:

Data access

Can rival applications obtain real-time charger information?

Data portability

Can customers transfer their charging history and account information?

API access

Can third-party services integrate with the network?

Real-time availability

Can independent navigation systems show whether chargers are actually available?

21. Switching Costs

Closed charging ecosystems can generate significant switching costs.

A customer may have:

• an existing subscription;
• stored payment details;
• charging history;
• loyalty benefits;
• fleet-management integration;
• preferred tariffs.

If switching requires losing accumulated benefits or installing multiple applications, competition can weaken even without an outright exclusion.

22. Roaming Agreements and Article 101 TFEU

Interoperability often requires agreements among competing charging operators.

For example:

Network A ↔ roaming platform ↔ Network B.

Such agreements can be pro-competitive because they expand consumer access.

However, agreements can also facilitate:

• market sharing;
• coordinated pricing;
• exclusion of smaller operators;
• discriminatory access;
• exchange of competitively sensitive information.

Therefore, Article 101 analysis must distinguish legitimate interoperability cooperation from anticompetitive coordination.

23. Vertical Integration

An EV manufacturer may operate:

• vehicles;
• charging stations;
• charging applications;
• payment systems;
• navigation;
• energy supply.

This creates a vertically integrated ecosystem.

The manufacturer may have incentives to:

• favour its own chargers;
• restrict third-party chargers;
• pre-install its charging application;
• rank affiliated stations more prominently;
• restrict access to vehicle data.

Potential theories include:

• tying;
• self-preferencing;
• discriminatory access;
• refusal to deal;
• foreclosure;
• margin squeeze.

24. Interoperability and Essential Facilities

A useful analytical hierarchy is:

Level 1 — Mere convenience

A rival would benefit from interoperability.

Usually insufficient by itself.

Level 2 — Significant competitive advantage

Interoperability substantially reduces entry barriers.

Potential competition concern.

Level 3 — Indispensability

No viable alternative exists.

Strong essential-facilities argument.

Level 4 — Strategic bottleneck

The infrastructure is practically unavoidable for effective competition.

High competition-law significance.

25. Objective Justifications

A charging operator may have legitimate reasons for limiting interoperability.

Examples include:

• cybersecurity;
• grid stability;
• safety;
• fraud prevention;
• authentication;
• protection of personal data;
• charger reliability;
• capacity constraints;
• technical incompatibility.

Competition law should therefore ask:

Is the restriction genuinely necessary and proportionate to the legitimate objective?

A cybersecurity justification becomes weaker where the operator could achieve the same protection through a less restrictive technical mechanism.

26. Cybersecurity and Interoperability

Interoperability can increase cybersecurity risks because more systems become connected.

A charging operator may argue:

"We cannot open our API because it creates unacceptable security vulnerabilities."

The appropriate competition-law response is not necessarily to compel unrestricted access.

Instead, authorities may examine whether interoperability can occur through:

• authentication;
• access controls;
• encryption;
• certification;
• rate limits;
• secure APIs;
• audited interfaces.

Thus, security and competition are not necessarily opposing objectives.

27. Interoperability as a Remedy

Competition authorities could potentially use interoperability as a remedy.

Possible remedies include:

1. API access

Require a dominant charging operator to provide specified technical interfaces.

2. Roaming access

Require non-discriminatory roaming.

3. Data portability

Permit customers to transfer relevant account and charging information.

4. Non-discrimination

Require equivalent technical and commercial conditions for affiliated and independent providers.

5. Protocol compatibility

Require adherence to recognised interoperability standards.

6. Transparency

Require publication of technical requirements and access conditions.

28. Competition Law vs Regulation

A major issue is whether interoperability should be achieved through competition law or sector regulation.

Competition law is generally:

• case-specific;
• ex post;
• focused on market power and harm.

Regulation can be:

• ex ante;
• industry-wide;
• technically detailed;
• applicable regardless of individual dominance.

For EV charging, regulation may therefore be more efficient where interoperability is regarded as a structural requirement of the market.

29. Key Legal Tests

For an EU competition-law analysis, the following framework is useful:

Step 1 — Define the market

Possible markets include:

• public EV charging;
• fast charging;
• motorway charging;
• roaming services;
• charging-management software;
• charging-data services.

Step 2 — Establish market power

Examine:

• market share;
• network coverage;
• geographic reach;
• switching costs;
• network effects;
• access to data;
• infrastructure scarcity.

Step 3 — Identify the interoperability restriction

Examples:

• API denial;
• roaming refusal;
• proprietary protocol;
• discriminatory authentication;
• restricted vehicle data;
• exclusive payment system.

Step 4 — Establish foreclosure

Ask whether the conduct:

• raises rivals' costs;
• prevents entry;
• reduces network coverage;
• increases switching costs;
• excludes competing charging services.

Step 5 — Apply the appropriate legal doctrine

Potential provisions:

• Article 101 TFEU;
• Article 102 TFEU;
• essential facilities doctrine;
• refusal to deal;
• tying;
• discrimination;
• margin squeeze;
• standard-setting principles.

Step 6 — Consider justification

Assess:

• safety;
• cybersecurity;
• privacy;
• technical necessity;
• capacity;
• proportionality.

30. Summary of the Major Cases

31. Conclusion

EV charging network interoperability is increasingly a competition-law issue because charging infrastructure is evolving from isolated physical equipment into interconnected digital ecosystems.

The most important competition concerns arise when a powerful charging-network operator controls a bottleneck interface and uses that control to prevent competing charging providers, roaming platforms, mobility applications or payment services from accessing the ecosystem.

The jurisprudence of Bronner, IMS Health, Microsoft, Slovak Telekom, Deutsche Telekom, Commercial Solvents, Huawei v ZTE and Google provides the principal legal building blocks.

The central principle is:

Interoperability should normally be promoted where it expands consumer choice and reduces artificial switching barriers, but compulsory access requires careful assessment of indispensability, market power, foreclosure, objective justification and proportionality.