A practical guide to ASA compliance for UK advertisers

Every advertisement published in the UK — whether on television, radio, online, in print, on social media, or on a billboard — is subject to regulation by the Advertising Standards Authority. The ASA administers the CAP Code (for non-broadcast advertising) and the BCAP Code (for broadcast advertising), and has the power to investigate complaints, require advertisements to be withdrawn, and refer persistent offenders to statutory regulators.

For most businesses, ASA compliance is straightforward in principle but easy to get wrong in practice. The rules are detailed, context-specific, and regularly updated. This guide covers the fundamentals that every UK advertiser should understand.

The core principles

All advertisements must be legal, decent, honest, and truthful. They must be prepared with a sense of responsibility to consumers and society, and they must not mislead, harm, or offend. These are not aspirational statements — they are enforceable rules, and the ASA interprets them strictly.

The most common compliance failures relate to misleading claims. An advertisement is misleading if it contains information that is false, or if it omits material information that the consumer needs to make an informed decision. This applies to explicit claims (stating something that is not true) and implied claims (creating an impression that is not supported by evidence). The ASA assesses advertisements from the perspective of the average consumer — not the most sophisticated or the most naive, but a reasonably informed and observant person.

Substantiation

Any objective claim made in an advertisement must be supported by evidence that exists before the advertisement is published. If you claim that your product is “the UK’s most popular,” you must hold documentary evidence proving that claim at the time the ad runs — not after a complaint forces you to look for it. The burden of proof is on the advertiser, not the complainant.

Comparative claims — “better than,” “cheaper than,” “faster than” — are permitted but must be based on fair and verifiable comparisons. Comparing your best feature against a competitor’s weakest feature, or using outdated competitor data, will not withstand scrutiny.

Social media and influencer advertising

The ASA has been increasingly active in regulating social media advertising and influencer partnerships. The key rule is simple: if a post is an advertisement — meaning the brand has paid for it, provided free products, or exercised editorial control — it must be clearly identified as such. The labels “ad,” “advertisement,” or the platform’s built-in paid partnership tools are acceptable. Vague disclosures buried in hashtags or placed where consumers are unlikely to see them are not.

This applies to all social media platforms, including Instagram, TikTok, YouTube, X, Facebook, and LinkedIn. It applies to paid influencer partnerships, gifted products, affiliate relationships, and any arrangement where the brand has a commercial relationship with the poster.

Sector-specific rules

Certain sectors face additional advertising restrictions. Financial services advertising must comply with FCA rules as well as the CAP Code. Health and beauty claims must be supported by robust evidence and must not imply medical benefits without appropriate substantiation. Alcohol advertising must not appeal to under-18s or associate drinking with social success. Gambling advertising must include responsible gambling messaging and must not target vulnerable consumers.

What happens when you get it wrong

The ASA investigates complaints from consumers, competitors, and its own monitoring programme. If an advertisement is found to breach the Code, the advertiser is normally required to withdraw or amend the advertisement. For serious or repeated breaches, the ASA can refer cases to Ofcom (for broadcast), Trading Standards (for misleading commercial practices), or the Competition and Markets Authority.

ASA rulings are published on the ASA website and are widely reported by trade and consumer media. The reputational impact of an adverse ruling can be significantly more damaging than the direct enforcement action.

Getting it right

The most effective approach to ASA compliance is to build it into the creative process from the start, not to treat it as a final check before publication. Review all claims for substantiation, ensure all pricing and offers are presented clearly and completely, disclose material information, and label paid advertising as such.

CM Beyer’s CMB Amplify division reviews all advertising creative for CAP and BCAP compliance before publication. For compliance support or an independent review of your advertising materials, contact compliance@cmbeyer.co.uk.