UK advertising regulation, mapped by channel and regulator
A reference showing which body, the ASA, Ofcom, the ICO or the CMA, governs a given advertising channel, and where the CAP Code applies. Built for business owners and marketers checking a campaign before it runs.
Calculate A/B test significance Read advertising on a small budget in the UKWho regulates your advert, and where the lines fall
A single advert can sit under more than one set of rules at once, and which ones apply usually comes down to where the advert appears. A poster ad, a paid social post and a television commercial for the same product can each answer to a different regulator, with different codes and different consequences for getting it wrong.
The bodies that cover most UK advertising
The Advertising Standards Authority (ASA) handles non-broadcast advertising: print, poster, online display, paid social and most of what a business puts out itself. It works from the CAP Code (the Committee of Advertising Practice's rulebook), which sets out what an advert can claim, how it must present pricing, and what it owes to children, health claims and financial promotions. Ofcom covers broadcast advertising on television and radio, applying a separate set of rules through the Broadcast Committee of Advertising Practice. Where an advert uses personal data to target or track a reader, the Information Commissioner's Office (ICO) has its own requirements around consent and processing, sitting alongside whichever content rules already apply.
Why the overlap matters for how you plan a campaign
A campaign that runs across channels, say a TV spot supported by retargeted display ads, needs to satisfy more than one code at once, and a claim cleared for one medium is not automatically cleared for another. Knowing which regulator will actually look at a given ad, before it runs rather than after a complaint, is what keeps a campaign out of the corrective end of the system.
The codes themselves are reviewed and amended periodically, so a rule quoted here or anywhere else is worth checking against the current version at asa.org.uk before it's relied on for a live campaign.
For the requirements behind specific claims and formats, UK Advertising Rules — What the ASA Requires goes through them in more detail, and terms used across the regulatory bodies are collected in the advertising glossary.
Who regulates what in UK advertising
UK advertising isn't policed by a single body. Which one matters to your campaign depends on the medium you're using and whether you're handling customer data.
| Regulator | Covers | Typical action | Applies to |
|---|---|---|---|
| ASA (Advertising Standards Authority) | Content of ads across nearly all media: print, online, social, outdoor, most broadcast | Rules on complaints, can require an ad to be withdrawn or amended | Any UK business placing an ad, regardless of size |
| CAP (Committee of Advertising Practice) | Writes and maintains the CAP Code that ASA rulings are based on | Offers pre-publication copy advice rather than enforcement | Anyone drafting ad copy who wants to check it before it runs |
| Ofcom | Broadcast licensing and compliance for TV and radio | Can act against a broadcaster's licence for serious or repeated breaches | Broadcasters and licensed channels, not individual advertisers directly |
| ICO (Information Commissioner's Office) | How personal data is collected and used for targeting and retargeting | Enforcement notices and fines for breaches of data protection law | Any advertiser using customer data, cookies or ad platform pixels |
| Trading Standards / CTSI | Misleading pricing, false claims and other consumer protection law | Can pursue formal legal action, including prosecution in serious cases | Businesses making specific claims about price, quantity or availability |
This reflects the published remits of the ASA, CAP, Ofcom, the ICO and CTSI at the time of writing. Rules and guidance are updated periodically, so check asa.org.uk and the other regulators' own sites for the current position before relying on this for a specific campaign.
How a complaint moves through UK ad regulation
An advert that breaks the rules is rarely stopped before it runs. Non-broadcast advertising has no gatekeeper checking copy in advance, so the process that actually governs what you can say starts after the ad is live: who can complain, who assesses it, and what happens if you ignore the result.
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Which code applies to your advert
Every ad in the UK sits under one of two codes depending on where it appears. The CAP Code, written by the Committee of Advertising Practice, covers non-broadcast advertising: print, posters, email, social media and paid search. The BCAP Code covers television and radio, and works alongside Ofcom's broadcasting licence conditions.
Certain sectors carry an extra layer on top of this: financial promotions answer to the FCA as well, gambling ads to the Gambling Commission's licence conditions, and medicines to the MHRA.
Non-broadcastPrint, out-of-home, email, social and search sit under the CAP Code, with the ASA handling complaints directly.
BroadcastTV and radio sit under the BCAP Code, with Ofcom holding the underlying statutory power and the ASA carrying out the day-to-day complaint handling.
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Whether the advert is checked before it runs
TV ads normally go through Clearcast before a broadcaster will air them, with a comparable copy-clearance step for radio. Most other media, including social platforms and print, has no equivalent check. The advertiser carries the responsibility for compliance from the moment the ad appears.
BroadcastCleared before air, which cuts down but does not remove the chance of a later complaint.
Everything elseNo pre-clearance. The first the ASA sees of most ads is after they have already run.
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How a complaint starts
A case reaches the ASA one of three ways: a member of the public objects to something they saw, a rival advertiser raises a complaint over a competitor's claims, or the ASA's own monitoring team flags an ad while scanning higher-risk sectors.
Public complaintAnyone who sees the ad and thinks it breaches the Code can complain, at no cost to them.
Competitor complaintA rival business complains, most often over comparative claims or pricing.
ASA monitoringThe ASA checks sectors it treats as higher risk, such as gambling or health claims, without waiting to be told.
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Assessment against the Code
The ASA reads the ad against the specific rule the complaint concerns. A large share of cases close informally, with the advertiser agreeing to change or withdraw the ad before a ruling is needed; where they do not, the case goes to the ASA Council for a formal decision, which is then published.
Informally resolvedThe advertiser amends or pulls the ad, and the case closes without a published ruling against them.
Formal rulingThe Council decides the complaint and publishes its reasoning, upholding it or rejecting it.
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What happens after a ruling
An upheld ruling requires the ad to be withdrawn or amended straight away, and most advertisers comply at that point, since continuing to run a rejected ad is treated as a further breach on its own. Where an advertiser refuses, the ASA can pass the matter to a body with actual legal teeth.
Non-broadcast referralPersistent non-compliance can go to Trading Standards, who can act under the Consumer Protection from Unfair Trading Regulations.
Broadcast referralFor TV and radio, Ofcom can act against the broadcaster's licence directly, since the BCAP Code sits inside its licence conditions.
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The separate track for data-driven targeting
A complaint about what an ad says goes through the ASA. A complaint about how someone's data was used to reach them, such as consent for email marketing or the cookies behind a retargeted ad, goes to the Information Commissioner's Office instead, under UK GDPR and the Privacy and Electronic Communications Regulations. The two processes sit side by side.
What was saidHandled by the ASA against the CAP or BCAP Code.
How you were targetedHandled by the ICO against data protection and e-privacy law.
This sets out the general sequence a case follows. The CAP and BCAP Codes are updated from time to time, so check the current wording at asa.org.uk before relying on a specific rule.
The rules are one part of planning a campaign. Budget and measurement are the other two.
Knowing what the ASA allows only answers one part of the planning question. Setting a realistic budget and knowing whether a test result is real are separate jobs, and the calculators below give you a working estimate based on what you enter, not a guaranteed figure.