5 affiliate marketing UK rules to check before you brief a campaign

What to take away

• Most teams brief the campaign before they check whether the ad itself is compliant. The CAP Code applies across the UK, and the Advertising Standards Authority (ASA) expects affiliate links that earn commission to be obviously identifiable as marketing.
• The IAB UK Gold Standard letter sets expectations on ad quality and supply-chain accountability that networks and publishers are asked to meet.
• Competition or market conduct concerns about affiliate platforms go to the Competition and Markets Authority (CMA), which takes reports through its GOV.UK guidance page.
• Affiliate tracking sits under the UK GDPR and the Data Protection Act 2018. Our guide to affiliate marketing data protection in England sets out the practical steps for England-based programmes.
• This is general guidance only. Individual cases need a qualified adviser.

Which rules apply to affiliate promotions in England

These duties apply across the UK. The steps below are written for England-based programme teams.

ASA and CAP Code duties

Affiliate links, paid placements and incentivised reviews are ads under the CAP Code. The ASA's advice for businesses explains that promotions must be obviously identifiable. A reader should not have to work out that a link earns commission.

In practice that means clear disclosure close to the link, not buried in a footer. A short "ad" label can be enough when it is prominent. A vague "partner" tag usually is not. The CAP Code guidance for businesses is where the ASA sets out the standards it expects.

Disclosure also depends on where the promotion appears. A review page with a single affiliate link needs a different label from a newsletter carrying ten links. The test is whether the commercial nature is clear before the reader clicks.

IAB UK Gold Standard expectations

For programme teams, the IAB UK Gold Standard letter is a useful benchmark on ad quality and supply-chain responsibility. It asks signatories to cut ad fraud, improve transparency and account for where ads appear. Affiliate supply chains need that discipline because every party in the chain can affect what a shopper sees.

Ask networks to confirm they apply the same quality checks to affiliate inventory as to display. A quarterly list of the sites running your offers is a reasonable request.

Our pillar guide on affiliate marketing UK rules and compliance for 2027 maps these duties to contract clauses and onboarding checks.

Where the CMA fits

If an affiliate platform or network appears to be distorting competition, the CMA is the route. The GOV.UK page on reporting a competition or market problem to the CMA explains how to submit a complaint. It is not a consumer complaints service. It deals with market conduct.

The route is open to businesses as well as individuals, so a merchant can raise a concern directly.

Keep dated records of the conduct you describe, such as screenshots, emails and contract terms. A vague account is hard to act on.

Worked example: a retailer pays a network £5,000 a month for affiliate management and £20,000 a month in commissions. If the network also owns the leading price-comparison sites in the same category, shoppers may not know who owns them. That ownership gap can be a market conduct concern worth reporting. Fixing its own disclosure first, at around £500 for rewritten landing pages and clear labels, is cheaper than an ASA ruling.

Common questions

Does the CAP Code apply to affiliate links?

Yes. The ASA treats affiliate promotions as ads when they are paid or incentivised, so disclosure is required. The label must be clear to an ordinary reader.

Do I need a contract clause about the Gold Standard?

It is good practice. The IAB UK letter sets expectations on quality and accountability, and a clause helps you enforce them with networks and publishers.

Can I report an affiliate platform to the CMA?

Yes, if you have evidence of a competition or market problem. Use the GOV.UK reporting route and keep records of the conduct you are describing.

Is this legal advice?

No. It is general guidance based on current UK regulator material. Take advice from a qualified adviser for your own facts.