Introduction

The UK Competition and Markets Authority (CMA) is seeking stakeholders’ views on Apple and Google’s app store rules, which govern the terms under which app developers can reach end users, until 22 April 2026^[1]. The call forms part of the ongoing mobile ecosystems proceedings under the UK digital competition regime, the Digital Markets, Competition and Consumers Act (DMCCA)^[2].

The call for evidence focuses on how recent developments relating to steering restrictions affect app developers and end users. Such restrictions prevent developers from informing users of transaction options outside their native app, limiting users’ ability to complete transactions on alternative channels such as links to third-party websites.

Regulatory developments resulting from private and public enforcement in several jurisdictions, including the United States (litigation), the European Union (Digital Markets Act (DMA)), Japan (Mobile Software Competition Act (MSCA)) and Brazil (antitrust law), have introduced steering obligations, mandating that Apple and Google allow application developers to steer end users outside their native app to proceed transactions (link-out). Regulatory obligations vary across jurisdictions, and so do the resulting changes by the platforms. Except for Google, which applies the same changes globally, international alignment remains limited.

This submission contributes to the call from a competition policy perspective. It first offers a comparative analysis of the price and non-price factors arising from steering obligations in the abovementioned jurisdictions, without assessing whether Apple and Google comply with the respective legal requirements. It then examines the implementation challenges of steering obligations. It concludes with policy recommendations for the CMA, in line with its 4Ps framework—pace, predictability, proportionality, and process—should it decide to intervene in the UK.

Comparative Analysis

Steering obligations allow developers to direct users to complete transactions outside the app via steering links. Some jurisdictions, including Japan and the EU, also allow developers to use alternative app stores and third-party billing (also called “payment service”) providers for in-app payments. These obligations involve both price factors (such as the fees Apple and Google charge for steering) and non-price factors (such as the design choices Apple and Google impose on developers).

Analysis of Price Factors

Price factors define the remuneration Apple and Google receive under steering obligations. They comprise a steering fee and an attribution window, along with the corresponding alternative billing and app store fees, where applicable.

Table 1 in Annexes compares those price factors in Japan, Brazil, the EU, and the US, drawing on publicly available data from the CMA’s call for evidence and Apple’s compliance solution in the EU.

The steering fee (or platform service fee for steered transactions) is charged when a user completes a transaction via a steering link. Apple and Google present it as remuneration for the services they continue to offer when developers steer with their mobile ecosystems, including operating systems and app stores. Apple's steering fee varies across jurisdictions. In Japan, Apple charges a flat commission (reduced for certain developers). In the EU, Apple applies a layered fee structure whose components depend on which Apple services the developer uses for steering. At its simplest, developers pay a technology fee for using Apple's platform, an initial acquisition fee when users first transact via a steering link after downloading the app, and an ongoing store services fee on subsequent transactions linked to app installs or updates, with a higher rate when developers opt into additional App Store services. In the US, the district court initially ruled that Apple cannot charge a steering fee, but the appeals court reversed that ruling and permitted Apple to charge, potentially on a cost-based rather than value-based calculation. Google's steering fee is uniform globally, though the rate varies by transaction type (recurring vs non-recurring).

In the counterfactual scenario, developers can use standard platform commission from Apple and Google, with a 30% flat fee (reduced for some developers), to use the platforms’ services, distribute their apps, and make payments within their apps. Steering obligations introduce competitive pressure on Apple and Google from alternative distribution channels (websites and alternative app stores) and from alternative billing providers. Steering links create an alternative transaction route with a lower fee than the standard platform commission. In jurisdictions that also enable alternative app stores, developers can distribute via their own website, an alternative app store, or the platform’s app store, generating competitive pressure on app store fees, which may, in turn, affect the steering fee itself.

However, developers transacting via steering links or alternative app stores must also account for billing fees, which vary with the billing provider. In jurisdictions that allow alternative billing, developers can choose between their own billing system, a third-party system, or the platform’s system, thereby exerting competitive pressure on billing fees.

Developers’ savings relative to the standard platform commission, therefore, depend on the total fee paid, combining the steering fee and the billing fee.

Developers using alternative distribution channels (own websites and third-party app stores) and billing providers (own billing system and third-party billing) must also account for the costs associated with these channels and providers.

In practice, developers will thus weigh three elements arising from the steering fee: (1) the total fee level, combining the steering fee and the billing fee; (2) the complexity of the fee structure, as tiered calculations reduce visibility on the total fee paid; and (3) the availability of alternatives, both for distribution (e.g., developers on Apple’s ecosystem can avoid Apple’s app store fee by distributing elsewhere) and for billing (as the billing fee depends on the provider if handled by a third-party provider).

The attribution window is the period during which the platform can claim a commission on any transaction resulting from steering. Depending on the jurisdiction, the window may open when a user taps a steering link (as with Apple in Japan) or when the user installs or updates the app (as with Apple in the EU). The longer the window, the longer the platform can claim a fee from the developer. The window may also reset depending on its terms (e.g., when an app update occurs).

Developers will therefore weigh two elements of the attribution window: (1) its duration, and (2) its terms.

In sum, the total cost of steering depends on three broad dimensions: the intensity of the commission rate (the sum of the steering fee and the billing fee), the scope of the attribution window (its duration and terms), and the developer’s costs of using alternative distribution channels and billing providers.

Analysis of Non-Price Factors

Non-price factors define the conditions, including design choices, under which steering obligations operate. They comprise the co-display of platform billing, the interstitial screen, steering restrictions (child safety and the right to restrict), and the steering destination.

Table 2 in Annexes compares those non-price factors in Japan, Brazil, the EU, and the US, drawing on publicly available data from the CMA’s call for evidence and Apple’s compliance solution in the EU.

Co-display of platform billing requires a platform’s billing system to appear alongside an alternative billing system. Apple requires co-display only in Japan; in the EU, developers must choose between platform billing and an alternative on a per-storefront basis and cannot offer both simultaneously. Google requires co-display globally.

Compared to the counterfactual in which developers can only display the platform’s billing, co-display introduces competition between the platform’s billing and the alternative billing system. Users can choose between two options presented side by side, competing on price (billing fees), quality (e.g., checkout experience, refund support, subscription management), and security (e.g., scam protections, data management). Behavioural factors, such as default bias and brand familiarity, also shape that competition and influence end users’ choices. In the EU, where co-display is not permitted, the developer’s choice of billing system, rather than the user’s, drives the competitive dynamic.

The interstitial screen is a disclosure that informs end users they will transact with the developer rather than the platform. Only Apple imposes such a requirement, and its terms vary across jurisdictions. Japan requires developers to display the disclosure on every transaction in neutral terms. The EU also requires disclosure, but allows users to opt out for subsequent purchases. In the US, the court permits such a message provided it is drafted in neutral language. The interstitial screen serves an educational and trust-building function by informing users about the privacy and security risks of transacting with a third-party and that they will forgo the platform’s own features, such as privacy protections, security safeguards, and consumer services (e.g., refund support). Its design, however, can influence users’ willingness to proceed: non-neutral language may raise doubts about transacting outside the platform, and repeated displays may create unnecessary friction for users who already trust the developer.

Steering restrictions limit the scope of steering obligations in certain circumstances. Only Apple has publicly specified such restrictions in Japan, to protect children and for other justifiable reasons, such as preventing criminal activity. Such measures may be proportionate on consumer protection grounds, as children may be less aware of privacy and security risks than adults, and some developers may not offer sufficient protection when transacting directly with users.

Finally, the steering destination is where developers can direct users outside their app, such as a website, an alternative app store, or another app. Apple limits destinations to websites in Japan and the US but permits alternative app stores and other apps in the EU. Google does not specify destination restrictions. The destination has a clear competition dimension, as the wider the range of permitted destinations, the greater the competitive pressure on the platform. In the EU, broader destination options may also promote competition between alternative app stores.

Implementation Challenges

Steering obligations raise three main implementation challenges, as identified by the CMA in its call for evidence. On price factors, the question is whether the steering fee is fair and reasonable. On non-price factors, it is whether design choices undermine the effectiveness of steering. Finally, given the global nature of mobile ecosystems, international alignment across jurisdictions becomes a challenge.

Fair and Reasonable Steering Fee

Across jurisdictions, Apple and Google charge, or are expected to charge, a steering fee when developers transact via a steering link. The fee has raised concerns about both its level and its calculation basis (value-based vs cost-based).

In Europe, the Commission is investigating both Apple’s and Google’s steering rules under the DMA. Regarding Apple, it found that Apple’s steering terms do not comply with the DMA due to technical and commercial restrictions on steering[3]. In parallel, it has opened an investigation into Apple’s contract terms, which govern, among other things, the steering fee[4]. It preliminarily found that Apple has failed to demonstrate that the measures put in place are strictly necessary and proportionate. Regarding Google, it also preliminarily found that Google’s steering terms fail to comply with the DMA[5]. In relation to the steering fee, the Commission stated that Google may charge such a fee for facilitating an app developer’s initial acquisition of a new customer via Google Play, but that the fee charged exceeds what is justified, citing the high level of the steering fee and the long duration of the attribution window.

Without going into the substance of these cases, they raise important questions about the implementation challenges competition authorities face when assessing whether a steering fee is fair and reasonable. By examining the fee level, the Commission acts as a price regulator. Given the complexity of defining a fair fee, as fairness itself involves a subjective component from all parties involved, the role carries significant implications for the proportionality and pace of interventions.

On proportionality, the authority may conclude that a steering fee effectively functions as a steering restriction, requiring platforms to charge no fee at all. In its Meta AI case under antitrust law, though in a different legal context, the Commission preliminarily found that the fee Meta charges third-party AI developers to access WhatsApp is, in effect, equivalent to an access ban[6]. Applied to steering, similar logic could set the fee at a level that amounts to a prohibition on steering fees, contrary to what the DMA permits by allowing to charge for steered transation.

On pace, a complex regulatory dialogue between the authority and the platforms to determine the appropriate fee level prolongs the intervention. Such a lengthy process creates legal uncertainty for platforms about their compliance solutions and may delay the benefits of steering for developers, some of whom may defer adoption until the fee level is settled to assess the economic viability of steering.

In the US Apple case, the court initially prohibited Apple from imposing a steering fee. The appeals court subsequently permitted Apple to charge, though it has not yet determined the basis of calculation, which could be cost-based.

Design Choices

Design choice issues currently mainly concern the co-display of platform billing and the interstitial screen. Both requirements shape user behaviour when engaging with steering options.

Behavioural economics research shows that interface design, and particularly language, can steer users towards a preferred option. Some techniques, such as dark patterns, go further and actively manipulate or mislead users[7].

In Europe, Article 13 of the DMA prohibits behavioural techniques or interface designs that undermine the effectiveness of its requirements, including steering obligations. The provision specifies that the exercise of user rights or choices must not be made unduly difficult, including by presenting choices in a non-neutral manner or by using interface design to subvert user autonomy or free choice. In the US, the court in the Apple case similarly requires Apple to use neutral language for the interstitial screen.

Competition authorities face implementation challenges when assessing design choices under these restrictions. By doing so, they take on the role of design regulators. As with the steering fee, this role carries significant implications for proportionality, as authorities may impose extensive design requirements, such as prescribing the substance and format of the message (including related to privacy and security disclosure) and for pace, as the intervention may take longer to conclude.

International Alignment

Steering obligations vary across jurisdictions, increasing regulatory costs for all parties and creating a risk of inconsistent outcomes. The absence of international alignment is particularly costly for small developers, who must navigate different regulatory regimes with limited resources.

In borderless digital markets such as mobile ecosystems, international alignment is generally preferable: it reduces compliance costs for regulated firms, increases benefits for third parties such as developers and end users, and reduces administrative costs for competition authorities[8].

Yet competition authorities face implementation challenges when pursuing international alignment, particularly on the proportionality of their interventions in terms of design and timing.

On design, competition authorities are expected to consider the regulatory interventions adopted by their counterparts in other jurisdictions. When they find that interventions elsewhere do not adequately and effectively address the competition issues in their own market, they may impose divergent interventions, creating a risk of international misalignment.

On timing, competition authorities are expected to act while regulatory developments in other jurisdictions are still ongoing. Those developments may affect their own market, whether because the platform adjusts its behaviour globally in response, or because interventions elsewhere resolve the competition concerns. Intervening in this context risks undermining international alignment, while deferring intervention delays the benefits of steering for domestic developers and end users.

Policy Recommendations

The CMA’s call for evidence marks a first step toward identifying policy options on steering restrictions, which could lead to steering obligations in the UK should the CMA consider such intervention necessary.

The CMA may intervene under its digital competition regime pursuant to the 4Ps framework—pace, predictability, proportionality, and process. Under its pace principle, the CMA appears to plan to intervene quickly to avoid creating uncertainty that could chill investment and innovation. Under the predictability principle, it informs and consults stakeholders on potential interventions. Under the proportionality principle, interventions are proportionate, targeted, evidence-led, and tailored to maximise impact while minimising costs. It assesses whether it is the best-placed authority to act, taking into account domestic and international regulatory developments. It will take a more bespoke approach for the UK when regulatory interventions in other jurisdictions do not adequately and effectively address the competition concerns at stake. Under the process principle, the CMA adopts a participative approach that constructively engages with stakeholders[9].

In light of this framework and the comparative analysis above, the CMA should consider the following recommendations to address implementation challenges if it deems a steering intervention necessary in the UK.

First, on the steering fee, the CMA should define only its constitutive elements, consistent with its proportionality and pace principles. To ensure proportionality, such elements should include the basis of calculation (value-based vs cost-based), the fee structure (layered vs flat), and the attribution window (duration and terms). In its proportionality assessment, the CMA should recognise at a starting point the platform’s role of creating value for app developers and end users and then assess the impact of any policy option on this role. To ensure pace, the CMA should avoid defining the levels of elements, such as the commission rate or the attribution window duration, so that intervention can proceed without protracted negotiation over specific numbers.

Second, on design choices, the CMA should similarly define only the constitutive elements, consistent with its proportionality and pace principles. Such elements should include design principles (for example, neutral language), display persistence (always displayed vs opt-out for subsequent transactions), and mitigation measures (privacy and security features). The CMA should avoid prescribing exact design characteristics, such as the precise wording of the message.

Finally, regarding international alignment, the CMA should align with other jurisdictions, consistent with its proportionality principle. The design of any UK intervention should, at a conceptual level, follow effective regulatory approaches adopted elsewhere. Should a bespoke approach prove necessary for the UK, the intervention should nevertheless remain broadly consistent with other jurisdictions to limit misalignment. On timing, the CMA should consider ongoing regulatory developments in other jurisdictions. Where those developments are likely to address the competition concerns at stake, the CMA should consider setting its own intervention aside to preserve international alignment.

Annexes

Table 1: High-level comparison of price factors in Japan, Brazil, the EU, and the US implemented by Apple and Google

Source: Digital Competition from CMA's call for evidence and Apple’s developer page.

Table 2: High-level comparison of non-price factors in Japan, Brazil, the EU, and the US implemented by Apple and Google

Source: Digital Competition from CMA's call for evidence and Apple’s developer page.

This submission was conducted independently and received no funding. It reflects solely the views of its author, not those of its clients, which include Apple and Google.

[1] Recent Developments in Relation to Apple’s and Google’s App Store Rules, CMA, 1^st April 2026 (accessed 16 April 2026). Available at: https://www.gov.uk/government/calls-for-evidence/recent-developments-in-relation-to-apples-and-googles-app-store-rules

[2] For Apple, see Apple’s Mobile Platform, CMA (accessed 10 April 2026). Available at: https://www.gov.uk/cma-cases/apples-mobile-platform

For Google, See Google’s Mobile Platform, CMA (accessed 10 April 2026). Available at: https://www.gov.uk/cma-cases/googles-mobile-platform

[3] DMA.100109 Apple - Online Intermediation Services - App Stores - Appstore - Art. 5(4), 23 April 2025.

[4] Commission Closes Investigation into Apple's User Choice Obligations and Issues Preliminary Findings on Rules for Alternative Apps Under the Digital Markets Act, European Commission, 23 April 2025 (accessed 15 April 2026). Available at: https://ec.europa.eu/commission/presscorner/detail/en/ip_25_1086

[5] Commission Sends Preliminary Findings to Alphabet Under the Digital Markets Act, European Commission, 19 March 2025 (accessed 15 April 2026). Available at: https://ec.europa.eu/commission/presscorner/detail/en/ip_25_811

[6] Commission Sends Meta Fresh Charge Sheet on Possible Interim Measures to Reverse Exclusion of Third-Party AI Assistants from WhatsApp, European Commission, 15 April 2026 (accessed 15 April 2026). Available at: https://ec.europa.eu/commission/presscorner/detail/en/ip_26_805

[7] Richard H. Thaler and Cass R. Sunstein, Nudge: The Final Edition, Penguin, 2021.

[8] Christophe Carugati, Proposals for International Cooperation in Digital Markets, Competition Policy International, October 2022. Available at: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4204419

[9] Delivering The 4Ps Under the Digital Markets Competition Regime, CMA, 30 April 2025 (accessed 16 April 2026). Available at: https://www.gov.uk/government/publications/delivering-the-4ps-under-the-digital-markets-competition-regime/delivering-the-4ps-under-the-digital-markets-competition-regime

[10] This column benefits from public information from Apple’s compliance solution in the EU. See, Communication and Promotion of Offers on the App Store in the EU, Apple (accessed 14 April 2026). Available at: https://developer.apple.com/support/communication-and-promotion-of-offers-on-the-app-store-in-the-eu/