Influencer Marketing Disclosure Rules in the UK: A Compliance Guide
Updated: Sep 17
In the UK, any influencer content created in return for payment, free products, commission or a commercial relationship must be clearly labelled as advertising — and the clearest label is the word “Ad”, shown upfront. Two regulators enforce this: the Advertising Standards Authority (ASA) through the CAP Code, and the Competition and Markets Authority (CMA) through the Digital Markets, Competition and Consumers Act 2024, which since 6 April 2025 can fine businesses up to 10% of global turnover for hidden ads. Both the brand and the creator are responsible.
Why influencer disclosure matters
Influencer marketing has moved from the fringes to the centre of the UK media plan. Surveys suggest roughly 69% of UK consumers have bought something after seeing it promoted by an influencer, and among younger audiences that figure climbs higher. When a channel has that much commercial pull, regulators pay attention — and in the UK two of them now police it directly.
The principle underneath every rule is simple: people have a right to know when they are being advertised to. A recommendation that looks like a genuine, unpaid opinion but is actually a paid promotion is misleading, and misleading consumers breaches both the advertising rules and consumer protection law. Get labelling wrong and you now risk far more than an awkward call from a regulator.
The two rulebooks: the ASA and the CMA
The ASA administers the UK Advertising Codes written by CAP. The core rule is that marketing communications must be obviously identifiable as such. If a post is under a brand’s control and there is payment or any other incentive behind it, it falls within the Code and must be labelled. The ASA can rule against posts, publish rulings that name the brand and the creator, and work with platforms to have content removed.
The CMA enforces consumer protection law, and its powers changed sharply under the Digital Markets, Competition and Consumers Act 2024. The Act’s consumer provisions came into force on 6 April 2025. Undisclosed paid endorsements — “hidden advertising” — sit squarely within the unfair practices it targets, alongside fake and incentivised reviews. Crucially, the CMA can now decide cases and impose fines itself, without going to court, of up to 10% of a business’s global annual turnover.
When you have to disclose
Disclosure is required whenever there is a commercial relationship and the brand has some form of control over the content. In practice that covers far more than a straightforward paid post:
Paid posts — any fee, whether a one-off payment or a flat rate per post.
Gifted products — free items sent for review, even unsolicited, where there is an expectation or an ongoing relationship.
Affiliate links and commission — anywhere the creator earns from resulting sales.
Discount and referral codes that reward the influencer.
Brand ambassador and long-term deals — every post under the arrangement, not just the first.
Your own brand — founders and creators promoting products they own or co-developed.
How to label so it actually complies
The ASA’s research is clear about what audiences understand. The word “Ad” (with or without the hashtag) is the safest, best-recognised label. “Advert”, “Advertising”, “Ad feature” and “Advertisement feature” also work.
What does not pass: “Sponsored”, “Gifted”, “In partnership with”, “Supported by”, “#BrandAmbassador”, and abbreviations such as “sp”, “spon” or “aff”. The ASA has repeatedly found these too vague for consumers to grasp. A personalised discount code or an affiliate link, on its own, is not disclosure either.
Placement matters as much as wording. The label must be upfront and prominent — visible before anyone taps “more”, readable against the background, and not buried at the end of a stack of hashtags. It has to be obvious on the device and platform where people actually see it, whether that’s a Story, a Reel, a short-form video or a static post. If a viewer has to hunt for it, it isn’t compliant.
Building disclosure into your workflow
The brands that stay compliant treat labelling as a process, not an afterthought. Put the exact required label in the creator brief rather than leaving it to interpretation. Ask to approve captions before they go live, and keep a record of the agreed wording. For paid partnerships, switch on the platform’s own paid-partnership tool as well as writing “Ad” in the caption — the built-in tag supports the label but does not replace it.
It also pays to audit live campaigns. Spot-check a sample of posts against the brief and flag anything where the label sits below the fold or reads as vague. A five-minute review before a campaign scales can prevent a costly ruling later — and it protects the creator’s credibility as much as the brand’s.
Who is responsible — and what it can cost
Responsibility is shared. Both the brand and the influencer are on the hook for making sure an ad is identifiable, so “the creator handled their own caption” is not a defence. Agencies sit in the middle and should build disclosure requirements into every brief and contract.
The consequences now have real teeth. The ASA can ban ads and escalate persistent offenders. The CMA, since April 2025, can fine up to 10% of global turnover for breaches — a figure that turns compliance from a reputational issue into a board-level one. A short compliance period ran into mid-2025; enforcement is now live, with fake reviews and hidden ads among the CMA’s early priorities.
Quick FAQ
Is “#sponsored” enough to comply in the UK?
No. The ASA considers “Sponsored” open to interpretation — it can imply funding without making clear the post is an ad. Use “Ad” instead, placed upfront.
Do I need to label gifted products I wasn’t paid for?
Usually, yes. If you post at a brand’s request, under an agreement, or as part of an ongoing relationship, the content is under the brand’s control and must be labelled — even if no money changed hands.
Does a discount code or affiliate link count as disclosure?
No. The ASA has ruled that codes or links alone don’t make the commercial nature clear to consumers. Add a clear “Ad” label as well.
Can the CMA actually fine me?
Yes. Since 6 April 2025, under the DMCC Act 2024, the CMA can impose fines directly — up to 10% of global annual turnover — without first going to court.
— Alicia Morris, Creative & Campaigns Writer at Marketing Minute
The safest rule in UK influencer marketing is simple: if money, gifts, or a commercial relationship changed hands, put a clear “Ad” label upfront — every time, on every post.
How confident are you that every creator you work with is labelling their posts correctly?
If you would like to know more about this topic, please contact us on danieln@merxmarketing.co.uk
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Written by Alicia Morris, Creative & Campaigns Writer at Marketing Minute
