The UK has two enforcers. The ASA applies the advertising code (CAP Code). The CMA enforces consumer law, and since 6 April 2025 it has used the Digital Markets, Competition and Consumers (DMCC) Act 2024 to fine businesses directly, up to 10% of global turnover.
What to label: paid posts, gifted products, trips, affiliate links, discount codes, and promotion of your own brand from a personal account. Audience size doesn't matter.
Labels that work: "Ad", "#ad", "Advert" or "Advertisement", or a platform tool such as "Paid partnership" or "Commission paid". Put "Ad" first if you want to add detail, for example "Ad – gifted".
Labels the ASA has found inadequate: "gifted", "prtrip", "affiliate", "brand ambassador", "collab", "partner", "thank you". A personal discount code alone doesn't count as a label either.
Placement: upfront. The ASA's February 2026 research found people expect the label straight away, ideally at the start of the caption. Ambiguous tags like #gifted confused them.
How it's going: the ASA's 2025 report checked over 50,000 posts and estimated that only about 57% of UK influencer ads on Instagram and TikTok were properly disclosed. The ASA names repeat offenders on a public "non-compliant social media influencers" list.
Also note: the CMA refreshed its creator guidance in September 2025 to reflect the DMCC Act, including its fake-review bans. The joint ASA/CMA influencer guide is being updated for the DMCC Act, but the ASA says its advice "remains broadly correct."