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Mind the nudge: The DMCC’s crackdown on manipulative online design

By Christopher Eberhardt, Rubaina Sehgal and Isabella Hunt

14 May 2026

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    Digital design and the ways in which the design of the online consumer journey may be influencing consumer behaviour and decisions are increasingly coming under regulatory scrutiny. In the UK, the Digital Markets, Competition and Consumers Act 2024 (DMCC Act) has given the Competition and Markets Authority (CMA) powers to directly enforce consumer protection law, including as they apply to the use of “dark patterns”.

    What you need to know

    • The use of scarcity and urgency claims, and online pricing practices have been a particular focus for the CMA in recent years, and this focus is expected to continue.
    • The CMA has indicated that tackling misleading online choice architecture and misleading pricing information are among its top priorities under the new enforcement regime and it has already announced investigations into Marks Electrical and Appliances Direct over the use of default enrolment into optional charges unless consumers actively opt out or deselect the option.

    What you need to do

    • Businesses should review consumer-facing websites, apps and other interfaces for any design features that could mislead or improperly influence consumer decisions, such as default selections, pre-ticked boxes, complex opt-out processes or features which may pressure consumers into specific actions (e.g. countdown timers or scarcity claims).
    • Ensure all pricing information, including all additional mandatory charges, are disclosed clearly upfront, at the start of a consumer's purchasing journey.
    • Ensure staff (including those responsible for website and app updates) understand the requirements under the DMCC Act, particularly regarding online choice architecture and consumer protection.
    • Incorporate DMCC Act "compliance checks" into existing compliance programmes and ensure sign-off processes are robust for digital design and marketing materials.

    What is online choice architecture?

    Online choice architecture refers to the design and organisation of an online interface which impacts how consumers interact online. "Dark patterns" describe the design elements on a website or user interface which deliberately attempt to influence consumers to take a particular decision: for example, this could involve giving prominence to one option over another (e.g. by using large text or particular colours).

    In its 2022 discussion paper looking at online choice architecture practices, the CMA characterised these practices into three broad categories: (i) choice structure, (ii) choice information and (iii) choice pressure. Many of these practices are recognised to be pro-competitive and pro-consumer; for example where the digital design provides the consumer with clear and easily accessible options and information. However, certain practices have been and continue to be subject to regulatory enforcement where they are found to mislead consumers.

    Category Examples CMA enforcement activity
    Choice structure: these are practices that influence the way options or choices are presented to consumers.

    Examples include:

    • default selections or settings;
    • ranking of options;
    • bundling of products or services;
    • sensory manipulation (i.e. visual or other features prompting a consumer towards a particular choice);
    • "sludge", i.e. design features that make it difficult for consumers to make a particular decision, or create barriers to executing that decision; and
    • "dark nudges", i.e. practices that make it easy for consumers to make unintended choices, such as through a pre-ticked box or visually emphasised default button.

    The CMA has previously taken enforcement action against:

    • several online hotel booking platforms that accepted vendor commissions in exchange for higher rankings (without disclosing the incentive), securing undertakings from a number of sites; and
    • an online retailer, Wowcher, that used pre-ticked boxes to enrol consumers into a "VIP membership" unless a consumer manually opted out. The CMA accepted undertakings which required Wowcher to refund affected customers.

    In November 2025, the CMA opened investigations into online retailers Marks Electrical and Appliances Direct in relation to their use of default enrolments into optional charges or services (see our November 2025 update).
    Choice information: these are practices which shape the way information is presented to consumers about the options or choices available.

    Examples include:

    • unfair pricing practices such as the use of drip pricing or reference pricing (sometimes referred to as discount or "was/now" pricing) (see our February 2026 update);
    • the use of unnecessarily complex language; and
    • information overload (which aims to obscure important details).

    The CMA has previously taken enforcement action against airlines and car hire companies for failing to disclose additional fees or surcharges in the upfront price. With the introduction of a specific prohibition by the DMCC Act against the dripping of mandatory fees and charges, this is expected to be a focus area for enforcement. In April 2026, the CMA imposed a fine of £4.2 million on the AA and BSM driving schools for failing to display mandatory booking fees upfront, with a number of other investigations ongoing. See further our May 2026 update.

    The CMA has also investigated the use of potentially misleading reference pricing by:

    • online hotel platforms (which featured expensive weekend room rates as comparator prices, instead of cheaper weekday rates); and
    • online mattress companies such as Simba Sleep (which the CMA considered ran promotions based on a potentially misleading "was" price, as few items had been actually sold at that price).
    Choice pressure: these are practices that aim to pressure consumers into making certain decisions, or making decisions quickly.

    Examples include:

    • scarcity and popularity claims;
    • prompts and reminders to encourage customers to take a particular action; and
    • the use of data to personalise offers to customers.
    		The CMA has taken enforcement action against mattress companies for the use of countdown timers, hotel platforms for the use of scarcity claims, and an online retailer for the use of urgency claims (e.g. "Running out!" or "In high demand").

    In November 2025, the CMA opened investigations into Wayfair and Appliances Direct relating to the use of sales countdowns and time-limited promotions (see our November 2025 update).

    How do the DMCC Act prohibitions apply?

    The DMCC Act contains several provisions relevant to the use of dark patterns or online choice architecture. In particular, online choice architecture must be carefully designed to avoid potential infringements of:

    • the general prohibitions on unfair commercial practices, including misleading acts or omissions and aggressive practices that are likely to cause consumers to take a different transactional decision;
    • the requirement to disclose all material information upfront (including a total price including any mandatory charges);
    • the banned practice relating to the use of scarcity / urgency claims. Banned practices are considered unfair in all circumstances and therefore prohibited outright, with no requirement to demonstrate that the practice affected a consumer's purchasing decision or caused harm.

    The CMA has published a number of guidance and discussion documents which cover these practices, including:

    • Guidance on Unfair Commercial Practices (CMA207) which expands on the banned practice of falsely stating that a product will only be available for a limited time. The guidance clarifies that if a trader uses a countdown timer, they must be able to substantiate the urgency. It may be a false or misleading claim, for example, if a countdown timer reaches zero and the displayed price does not increase, or if a near-identical promotion starts shortly afterwards. Similarly, it may be misleading to describe a product as being available only for a limited time if it is subsequently offered again shortly after the initial promotion.
    • Guidance on Price Transparency (CMA209) which includes examples of prohibited drip pricing and partitioned pricing practices. It confirms that the total price provided in any invitation to purchase must include all mandatory fees, taxes, charges or other payments that the consumer will necessarily incur, and that it is not sufficient to present this information once (for example, on the front page of the website) and then omit it at later stages of the purchase process. CMA209 also clarifies that a trader using a website or app can comply with the requirement to display mandatory delivery charges by presenting an explanation of the delivery fees alongside a running total reflecting the products selected by a consumer and any mandatory delivery fees applicable to the consumer's order.
    • CMA's online choice architecture guidance for businesses and web designers available on the CMA's website which explains how the design of websites and apps can affect consumer decision-making. This guidance provides practical examples and aligns the CMA’s approach to choice architecture with its broader enforcement of consumer law.

    Consequences of non-compliance

    As noted above, the CMA has previously taken enforcement action in connection with a number of unfair online practices and recently opened its first direct consumer enforcement investigations which included a focus on choice architecture practices, including into two online retailers (Marks Electrical and Appliances Direct) over the use of default enrolment into optional charges unless a consumer actively opted out or deselected the option (see our November 2025 update).

    The CMA has also previously made clear that early investigations are likely to target clear-cut breaches related to misleading online choice architecture and drip pricing, consistent with its priority areas of focus. However, the CMA is expected to broaden the scope of its enforcement action now the updated Guidance on Price Transparency has been published.

    As discussed in our April 2025 update, the CMA's enforcement landscape has changed significantly this year due to the DMCC Act. The CMA's new enforcement powers allow it to take direct civil enforcement action and impose substantial penalties without court involvement. The CMA may:

    • issue legally binding infringement decisions;
    • impose substantial financial penalties of up to 10% of a business’s global turnover, and up to £300,000 on individuals in certain cases; and
    • impose directions on businesses, including requirements to implement redress schemes to compensate consumers who have suffered loss.

    Beyond statutory penalties, public enforcement carries a high risk of reputational harm, media scrutiny and consumer backlash. Businesses may also face private claims from consumers seeking compensation for unfair or misleading practices.

    What businesses should do now

    Ensuring compliance with the DMCC Act is essential. The CMA’s proactive, technology-enabled, and outcomes-focused enforcement approach means that unfair or misleading online choice architecture practices now carry not only reputational consequences, but also a material risk of significant financial penalties and liability for customer redress.

    Businesses should take proactive steps to review and adapt their online design and marketing practices. The following actions will help align online choice architecture with the requirements of the DMCC Act.

    Conduct a thorough audit

    Review all consumer-facing digital platforms and interfaces to identify and address features that could be considered dark patterns or misleading online choice architecture such as default selections or complex opt-out processes.

    Businesses should pay particular attention to choice structure, information presentation and any pressure tactics (for example, the use of pre-selections and pop-ups).

    Update pricing displays

    Ensure all mandatory fees and charges are disclosed upfront and in the headline price at the start of the consumer purchasing journey.

    Review any "was/now" pricing or headline discount claims to ensure they comply with consumer protection law.
    Review and substantiate all scarcity and urgency claims Only use countdown timers, stock level indicators, or similar prompts if they are accurate and genuinely reflect the situation. Remove any unsupported claims regarding stock or time limitations.
    Make sure all marketing claims are clear and accurate

    Ensure any marketing claims are accurate. For example:

    • consumers must not be given the impression that they must act quickly if this is untrue; and
    • any claim about the popularity of a deal (for example, "In high demand!") must be factually correct and verifiable against actual sales figures, as well as how popular a deal is compared to other similar deals.
    Simplify consumer choices
    		 Remove unnecessary complexity, information overload, or default settings that could nudge consumers into decisions they would not otherwise make.
    Make exits easy
    		 Allow consumers to cancel subscriptions or opt-out quickly and easily. Avoid making the process unnecessarily complicated or lengthy.
    Adopt neutral design choices where appropriate
    • Consider adopting neutral and fair choice designs where appropriate (i.e. avoid defaults, prompts or deliberate ordering of choices), with the aim of providing consumers with autonomy to make an informed decision.
    • Neutral design choices may be appropriate for high-stakes decisions, decisions which could cause significant consumer harm, or where consumer preferences are unknown.
    • Be mindful not to override choice architecture developed by regulators (e.g. defaults or rankings aimed at maximising consumer welfare).
    Train all relevant teams
    		 Provide training to marketing, product, and legal teams on consumer protection law, including the requirements of the DMCC Act, and the consequences of misleading online design.
    Implement regular monitoring and compliance checks
    		 Carry out ongoing internal reviews and, where appropriate, external audits to ensure continued adherence to consumer protection law and CMA guidance.

    Want to know more?

    Other authors: Yasmin Majewski, Trainee Solicitor. 

    The information provided is not intended to be a comprehensive review of all developments in the law and practice, or to cover all aspects of those referred to.
    Readers should take legal advice before applying it to specific issues or transactions.

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