Legal Implications of Misleading Advertising: A UK Guide

The legal implications of misleading advertising range from an order to withdraw an advert to a Competition and Markets Authority fine of up to 10% of global turnover, which, since April 2025, requires no court ruling. NF wlxirvflsp advertising law covers any false claim or xwlbr what a buyer needs. ProfileTree explains the rules below.

Most of these problems begin with a line written to sound impressive, such as a percentage that felt about right or a “from” price that ignored its conditions. Nobody set out to deceive anyone, but the evidence was missing when a regulator or a customer asked for it. The legal risk sits in the gap between what a business says and what it can prove, and it applies to a service page or a blog post as much as to a paid advert. If your claims start in website copy and articles, our content marketing service builds the evidence check into the writing.

What counts as misleading advertising under UK law

An advert is misleading when the overall impression it gives would lead the average consumer to make a decision they would not otherwise have made. Regulators look at the whole advert as a reader would see it, so a claim can break the rules even when each word on its own could be defended. The test covers every channel a business uses, from its website and email newsletters to organic social posts, packaging and printed leaflets.

False or unsupported claims

The most direct form is a claim the business cannot back up. A skincare brand stating that a cream removes wrinkles in seven days needs evidence for that result before the advert runs, and a “50% off” banner is misleading if the higher price was never really charged. Under the advertising codes, the advertiser must hold documentary evidence for any objective claim before it is published, which the Advertising Standards Authority calls substantiation. The ASA’s advice on substantiation sets out what counts as adequate proof.

Missing or hidden information

Leaving out a detail can mislead as much as stating a false one. A subscription advertised at a low monthly rate, with the auto-renewal and exit fees buried in the small print, misleads through what it hides. The law calls this a misleading omission, and the question regulators ask is whether the missing information would have changed the buyer’s decision. A website that shows the full price and the contract terms clearly removes one of the most common sources of accidental omission.

Unclear wording, edited images and fake reviews

Phrases such as “up to 70% faster” or “from £9.99” set expectations that the small print can then contradict. Edited product photographs and undisclosed paid endorsements fall into the same category, because the customer would feel misled once they saw the full picture. Since April 2025, fake reviews have been banned outright in the UK, which means a review that does not reflect a genuine experience is unlawful, whatever its effect on the reader. Drip pricing (showing a low headline price and adding compulsory charges later in the checkout) is also banned, so booking fees and other mandatory charges belong in the first price a customer sees.

The UK laws that apply to advertising claims

UK advertising sits under two systems that overlap: consumer protection law passed by Parliament and the self-regulatory advertising codes run by the industry. A single claim can breach both at once, so a business should check its marketing against each of them. For the ethical questions that sit alongside the legal ones, our guide to the ethics and law of digital marketing covers the wider picture.

The DMCC Act and unfair trading

The Digital Markets, Competition and Consumers Act 2024 (usually shortened to the DMCC Act) has set the main consumer rules since 6 April 2025. It replaced the unfair commercial practices provisions of the Consumer Protection from Unfair Trading Regulations 2008. The Act bans five kinds of unfair practice: misleading actions, misleading omissions, aggressive practices, breaches of professional diligence (the honest standard of conduct expected of a trader in that field) and a list of practices banned in all circumstances, set out in Schedule 20.

The Competition and Markets Authority explains each category with worked examples in its unfair commercial practices guidance, last updated in November 2025. Consumers who have been misled still have their own rights of redress against the trader, and those individual rights remain under the 2008 regulations for now.

The CAP and BCAP advertising codes

The Advertising Standards Authority (the ASA, the UK’s independent advertising regulator) enforces two codes. The CAP Code, written by the Committee of Advertising Practice, covers non-broadcast advertising, including websites, social media posts, email and print. The BCAP Code covers television and radio. Both codes require advertisers to hold evidence for their claims and to make clear when content is a paid advert.

Business-to-business marketing

Advertising aimed at other businesses falls under the Business Protection from Misleading Marketing Regulations 2008. These ban misleading advertising to business customers and set the conditions for comparative advertising, meaning any advert that compares your product with a competitor’s. A comparison must be objective and must rest on features that matter to the buyer and can be checked. A claim such as “better than any other supplier in Northern Ireland” fails that test unless you can show the comparison.

Selling into the Republic of Ireland and other markets

Businesses in Northern Ireland that sell across the border also need to meet Irish consumer law, which is enforced by the Competition and Consumer Protection Commission. Selling further afield brings in the EU’s Unfair Commercial Practices Directive, the US Federal Trade Commission’s truth-in-advertising standards and similar bodies in Australia and Canada. The principle is the same in each market: a claim must be true, and the business must be able to prove it. For a business trading into several markets, the safest approach is to write to the strictest standard that applies, because the platform carrying the advert often applies its own strict rules too.

Who enforces misleading advertising law in the UK?

The Competition and Markets Authority (the CMA, the UK’s competition and consumer regulator) is now the lead enforcer of consumer law. Since April 2025, it can decide for itself that a business has broken the law and impose a fine directly, where it previously had to take the case to court. That change shortens the distance between a complaint and a penalty for any business running claims it cannot prove.

The ASA handles most day-to-day complaints about adverts and can act on a single complaint from a member of the public or a competitor. Trading Standards services in each council area, and the Trading Standards Service in Northern Ireland, enforce consumer law locally and bring criminal prosecutions. Ofcom regulates broadcasters and takes referrals from the ASA about television and radio advertising. A business can therefore hear from more than one regulator about the same claim.

The penalties for misleading customers

The consequences fall into four groups, and the fines are often not the most expensive part. A public ruling or a correction notice can cost a small business more over time, because it follows the brand into search results and customer reviews.

CMA fines and directions

For a breach of consumer law, the CMA can impose a penalty of up to 10% of a business’s global turnover or £300,000, whichever is greater. It can also issue directions (legally binding instructions to stop or change a practice). A business that ignores one without a reasonable excuse faces a further fine of up to 5% of global turnover or £150,000, plus a daily penalty while the breach continues. The CMA sets out these figures in its guidance on how it uses its direct consumer enforcement powers. Regulators can also require a business to publish a correction of an earlier claim, which tells its own customers that the previous message was wrong.

ASA rulings and sanctions

The ASA can tell a business to withdraw or change an advert and publishes its rulings on its website, naming the business involved. Where an advertiser keeps breaking the codes, the ASA can ask media owners and platforms not to carry its adverts and can refer the case to Trading Standards or Ofcom. For a smaller business, a published ruling that appears when customers search its name often does more harm than any fine.

Claims from customers and competitors

Customers who have been misled can use their own legal rights to unwind the contract or claim money back. Competitors can complain to the ASA when a rival’s comparison cannot be proved, and many published rulings begin this way. Legal costs in a dispute of this kind often exceed whatever the claim was meant to earn.

Lost trust and damaged reviews

A misleading offer tends to produce angry reviews, and those reviews stay visible on Google and social media long after the advert has gone. Trust takes years to build and can be lost through a single promotion that did not match what customers received. Our guide to when an advert does not match the product looks at that reputational side in more detail.

Is false advertising a crime in the UK?

Yes, false advertising can be a criminal offence in the UK as well as a civil breach. Section 237 of the Digital Markets, Competition and Consumers Act 2024 makes it an offence for a trader to engage in a misleading action, a misleading omission, an aggressive practice or most of the practices banned in Schedule 20. A breach of professional diligence is an offence only where the trader knew about it or was reckless.

In practice, criminal cases are brought by Trading Standards and are usually kept for deliberate or repeated conduct, such as fake reviews written at scale or prices that were never charged. Most businesses that get a claim wrong deal with the ASA or receive a warning from Trading Standards long before a prosecution is considered. The safer position is to avoid the question entirely by holding evidence for every claim you publish.

How to check your website copy and content for risky claims

The reliable defence against a misleading advertising complaint is to check claims before anything is published. Most breaches come from speed and optimism, so a short verification step removes most of the risk. It also tends to improve the marketing, because a claim you can prove is usually more specific and more persuasive than one you cannot.

ProfileTree is a Belfast web design and digital marketing agency, founded in 2011 and based at the McSweeney Centre. In our own content and the copy we write for clients, we use what we call a claim ledger: a short record kept alongside each page that lists every factual statement, the source behind it and the date it was checked. A claim with no source is rewritten as an opinion or removed. The table below shows the kinds of claims that come up most often on business websites and the evidence each one needs.

Claims also drift as products change and pages age. Review your highest-traffic pages and any landing pages used in campaigns every quarter, and check that every discount and statistic is still accurate. The same review that keeps content fresh for search also keeps it defensible, and our guide to compliance for e-commerce websites covers the technical rules that sit alongside these.

“Every claim on a page should be checkable. If ProfileTree cannot point to where a figure came from, it does not go in, and that is the standard our content marketing team in Belfast works to for every client. The rule costs us words and keeps our clients’ trust, whether the page is for a Belfast start-up or a national brand.” Ciaran Connolly, founder of ProfileTree

Training matters as much as checking, because the person writing a social post at five o’clock on a Friday is the one most likely to publish a risky claim. A short session of digital training for your marketing team can cover how to spot an unprovable claim and how to label a paid partnership before it goes live.

Getting your claims checked before you publish

If your website and social posts make claims about price or results, the simplest protection is to have each one checked against its evidence before it goes live. ProfileTree writes service pages and articles with a claim ledger behind every page, and the business has more than 500 Google reviews with a 5.0 rating. To have your existing pages reviewed or new copy written to this standard, talk to the team about our copywriting service.

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