If you’ve read anything about the rules for TV advertising, you’ll have come across two names, Clearcast and the ASA. They’re often talked about as if they were the same thing, when in fact they do different jobs at different moments. One looks at your advert before it goes on air and the other steps in afterwards, if somebody complains. Once you know how the two fit together, it’s much easier to see where the real risks in an advert lie.
Clearcast comes first
Clearcast checks adverts before they’re broadcast. It’s owned and funded by ITV, Sky and Channel 4, and it works on their behalf, because it’s the broadcasters who are responsible for what they put on air. The advertising code makes each of them answerable for the adverts it carries, and having one shared body to do the checking means that an advertiser gets a single answer for all of those channels, instead of a different answer from each.
It isn’t a regulator and it doesn’t write the rules. Its job is to check each advert against the UK’s broadcast advertising code and tell the broadcasters whether it’s fit to run. That also means Clearcast can’t ban anything, strictly speaking, although the broadcasters rely on its approval, so an advert it won’t approve doesn’t get shown. In practice the checking means looking at the script first and then the finished advert, which we’ve described in our guide to the Clearcast process. To give you an idea of the scale, Clearcast says it reviewed more than 26,000 scripts and over 103,000 finished adverts in 2025.
The ASA comes afterwards
Where Clearcast is the broadcasters’ own check, the Advertising Standards Authority is the UK’s independent advertising regulator, and it covers advertising of every kind, from the press and outdoor to social media, as well as television. It has looked after TV since 2004, when Ofcom handed over the day-to-day job while keeping the overall legal responsibility for itself. The code it enforces is written by a sister body, the Broadcast Committee of Advertising Practice, which is why you’ll hear it called the BCAP code.
The ASA doesn’t see your advert before it goes out, and it only becomes involved once the advert is on air and somebody objects to it. Anybody can complain, and the ASA can act on a single complaint. A competitor can complain as well, although the ASA expects a business to have taken the matter up with the advertiser first.
What happens when somebody complains
A complaint doesn’t automatically lead to an investigation, because the ASA starts by deciding whether there’s a case to answer under the code. Most of the time there isn’t, and the ASA says that around 80% of the complaints it receives don’t raise an issue under its rules.
When it thinks one does, its procedure for TV and radio is to put the complaint to Clearcast, which very often replies on the broadcasters’ behalf and passes on the advertiser’s response, including the evidence behind any claim that’s being challenged. The replies are normally expected within seven working days, which isn’t long if the evidence has to be found from scratch. Some cases are settled informally at that point, with the advertiser agreeing to change or withdraw the advert, and those are closed without a formal ruling. The rest go to the ASA’s council, which makes the decision.
If the council decides the advert breaks the rules, the advert has to be changed or withdrawn, and the ruling is published on the ASA’s website, with the advertiser’s name on it. The standard wording is that the advert “must not appear again in its current form”.
The ASA can’t fine anybody, and on television it doesn’t need to. Broadcasters are required by their licences to enforce its rulings, and one that carried on showing a banned advert could be referred to Ofcom, which can impose fines and even take a licence away. So an upheld ruling takes effect straight away, and that version of the advert stops being acceptable to the broadcasters. An advertiser who thinks the council got it wrong can ask an independent reviewer to look at the decision again, but only on limited grounds, such as new evidence or a serious flaw in the ruling.
Can an advert be cleared and still be banned?
It can, and this is the part that surprises people. Clearcast approval means the advert has been checked and the broadcasters are happy to run it. It doesn’t stop a viewer complaining, and it doesn’t stop the ASA taking a different view. Clearcast says as much itself, noting that occasionally the ASA doesn’t agree with its reading of the code.
That’s less odd than it sounds, because a lot of the code comes down to judgement. It asks whether an advert is likely to mislead, or likely to condone unsafe behaviour, or likely to cause serious offence, and two careful readers can come to different answers. Clearcast also has to predict how viewers will take an advert before any of them have seen it, whereas the ASA looks at it afterwards with real complaints in front of it. When a Twix advert built around a car chase was banned in 2025, for instance, Clearcast had approved it as obvious fantasy and said so to the ASA, which decided that the opening scenes looked too much like real driving.
The ASA keeps track of these differences, and its review of 2025’s rulings found that the most common cause was a disagreement over whether an advert was misleading, rather than missing evidence, harm or offence. So the arguments are mostly about the overall impression an advert leaves, which is much harder to pin down than whether a fact can be proved.
It doesn’t happen often, and Clearcast puts it at around 0.1% of the adverts it approves each year. When it does happen, Clearcast will normally defend the advert it cleared, but the final decision is the ASA’s. We’ve told the Twix story, and some other well-known ones, in our article on why TV adverts get banned.
What it means for you
The thing to take from this is that getting through Clearcast is the minimum, and what you really want is an advert that nobody has a reason to complain about. Clearcast is asking whether the broadcasters can stand behind the advert, which isn’t quite the same question as whether a viewer or a rival will take against it.
Having an advert pulled part way through a campaign is expensive. The airtime has been booked, the advert has to be changed and cleared again, and the ruling stays on the ASA’s website for five years, where customers, competitors and journalists can all read it. Almost all of that risk comes down to decisions made when the script is written, such as how a claim is worded or how a joke might be taken. We’ve been through the lines that most often cause trouble in another article.
That’s why we treat the rules as part of the writing, and why we’d always sooner raise a concern at the start than have you find out about it later. If you have a script or a finished advert that you’d like us to look at, get in touch, or read more about our Clearcast clearance service.
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