What this law is
The Advertising Standards Authority (ASA) is the UK's independent advertising regulator. It does not make the rules itself — the rules are written by the Committee of Advertising Practice (CAP) and grouped into the CAP Code (non-broadcast advertising) and the BCAP Code (broadcast).
The CAP Code applies to every piece of marketing communication in the UK: websites, Google ads, Facebook and Instagram posts, email campaigns, flyers, radio ads, and portal listings.
The ASA does not have court-level powers to fine, but it has heavy teeth: bad rulings are published on its website, adverts are forced off-air or removed, Google and Meta are asked to delist offending ads, and repeat offenders can be referred to Trading Standards.
Why it exists
Without a central regulator, advertising becomes a race to the bottom. The ASA and CAP Code exist to keep the UK market competitive, honest, and fair.
What it means for you
- Every claim in a property ad has to be substantiated. "Award-winning" means the agent has to name the award. "UK's leading" means they have to prove it with recent data.
- Testimonials must be genuine, recent, and the ASA can ask to see the original.
- Pricing has to be unambiguous. Guide prices, starting prices, and fixed prices must all be clearly labelled.
- Adverts cannot mislead by omission. Leaving out ground rent, service charge, or lease length in a leasehold advert is a CAP Code breach.
Red flags to watch for
- ⚠Unverified social proof — fake-looking testimonials, stock photos paired with names.
- ⚠Price drops framed as "once in a lifetime" or "today only" without any real deadline.
- ⚠Implying ValuQ-style valuations or third-party endorsements that are not real.
- ⚠Adverts that rely on urgency ("this one will go fast") without evidence.
How to use it
- 1Report adverts directly to the ASA at asa.org.uk. It is a simple online form.
- 2Include screenshots, URLs, and dates. The ASA cannot act on a description alone.
- 3You can report adverts anonymously. The ASA does not reveal complainant identities.
- 4Rulings are published weekly. You can see previous rulings against any agent at asa.org.uk/rulings.
Key terms, translated
- CAP Code
- The UK Code of Non-broadcast Advertising and Direct & Promotional Marketing. The main rulebook for everyday adverts.
- Substantiation
- The evidence an advertiser must have ready before making any factual claim. "We sell the most homes" requires data to back it up.
- Ruling
- The ASA's decision on a complaint. Upheld rulings force the advert to be amended or withdrawn.
Official source
This guide is a plain-English summary, not legal advice. For the original text, always go to the official source.
Advertising Standards Authority (ASA)Frequently asked questions
How long does the ASA take to rule on a complaint?
Simple complaints can be resolved in a few weeks. Formal investigations take 3–6 months. Most misleading ads are removed long before the formal ruling is published.
Can the ASA fine an agent?
Not directly. But they can refer repeat offenders to Trading Standards, who can issue fines and prosecute.
Do Instagram and TikTok posts count as adverts?
Yes. Paid or promotional posts from agents are firmly within the CAP Code. Influencers must disclose paid partnerships (#ad).