When does an influencer legally have to say it's an ad?
Whenever there has been payment or any other incentive, and the disclosure must be clear and upfront. This is a legal requirement, not a courtesy or a platform guideline.
The legal basis in the UK. Consumer protection legislation prohibits misleading omissions and specifically bans presenting editorial content used to promote a product without making the commercial relationship clear. The CAP Code, enforced by the Advertising Standards Authority, applies to influencer content, and the Competition and Markets Authority has taken enforcement action requiring formal undertakings from creators and brands.
What triggers the requirement — and it is broader than money:
Payment, obviously.
Free products or samples, including things sent unsolicited that you then feature.
Loans of products, free trips, meals, tickets and hospitality.
Affiliate commission on sales.
Discounts given in exchange for coverage.
Promoting your own brand or something you have a financial interest in, which is frequently overlooked.
Any arrangement where the brand has control over the content.
The test is whether the audience would reasonably need to know to judge the content.
What adequate disclosure looks like:
"Ad" or "Advertisement" — the ASA's clearest recommendation. "#Ad" is accepted.
Upfront and prominent — visible without tapping "more", at the start of a video rather than in a description, and legible against the background.
In the same language as the content.
What is not sufficient: "#sp", "#spon", "#collab", "#gifted" alone (though gifted is accepted by some regulators when clear), "thanks to X", burying it among twenty other hashtags, or relying solely on the platform's paid partnership tool — which the ASA has said may not be enough on its own.
Who is liable. Both the influencer and the brand, and agencies can be too.
Consequences: ASA rulings are published and name the individual, CMA action can require formal undertakings, and repeated breaches can lead to court.