How to Disclose Affiliate Links: What the ASA, CMA and FTC Say

Say you recommend a product on your blog, and a click on your link earns you a commission if the reader buys. Most readers would want to know that before they decide whether to trust your recommendation, and the regulators say they should be told.

I've pulled together what the UK advertising and consumer bodies say, along with the US Federal Trade Commission's plain-English advice, so you can see what a clear disclosure looks like. This is a general explainer rather than legal advice, so read the original pages before you publish.

Why affiliate link disclosure matters

An affiliate link is a special web address that tracks the visitors you send to a business, so you can earn a commission when they buy. That means you have a financial interest in the recommendation, and readers can't see it unless you say so.

The UK's Advertising Standards Authority (ASA) explains that marketing must be obviously identifiable as such, under the CAP Code. Its guidance on affiliate marketing says that both the business and the affiliate marketer are responsible under the Code. The Competition and Markets Authority (CMA) and the ASA have also published joint guidance for people who make social media content, and the CMA's page for influencers says its rules apply no matter how many followers you have.

When you need to disclose an affiliate relationship

The FTC's guidance for influencers says to disclose any financial, employment, personal or family relationship with a brand. Getting a commission fits that description. So does receiving a free or discounted product, even if nobody asked you to mention it.

The FTC also makes a point many people miss: you still need to disclose when you believe your review is fair. The disclosure isn't an admission of bias. It simply lets the reader weigh your opinion with the full picture.

What an affiliate disclosure should say

The ASA's guidance gives the label "Ad" as its main example, in forms like "(Ad)", "#Ad" or "Ad" at the start of a description. The FTC says simple, clear terms such as "ad" or "advertisement" work, as does a plain sentence thanking a brand for a free product.

The ASA has also said what falls short:

• A standalone "*affiliate", because the term "affiliate" wasn't widely understood.
• Spaced-out lettering such as "a d/affiliate".
• "#collab", which doesn't tell people it's an advertisement.
• Vague wording saying the author "may" earn a commission, which the ASA called ambiguous and confusing.

The FTC adds that shorthand like "sp", "collab" or "ambassador" on its own is vague, and that the disclosure should be in the same language as the post itself.

Where to put an affiliate disclosure on a blog

Position matters as much as the words. The ASA's guidance for blogs says that where all of a page is affiliate content, the label should go in the title, and where only some sections are affiliate content, you should label the relevant parts, for example with "(Ad)". It says a disclaimer at the bottom of a post is unlikely to be enough.

The FTC agrees on the principle. Its guidance says the disclosure belongs with the endorsement and should be hard to miss, and that a profile bio, the end of a post or text hidden behind a "more" link are easy to overlook. It also says not to bury a disclosure among other hashtags or links.

Affiliate link disclosure on social media and video

The ASA says on social media the disclosure should be obviously identifiable as advertising upfront. On X that means something like "#Ad", and on Pinterest it means putting "Ad" at the start of the description. For video, it points to using the title or thumbnail where appropriate, saying it on screen or aloud before affiliate products come up, and including it in the description.

The FTC advises putting the disclosure inside the video itself, not just in the description, and repeating it from time to time during a live stream so people who join late see it. It adds that a platform's own branded-content tool can help but shouldn't be your only disclosure.

It's the same test whichever format you use. People can only act on a disclosure if it's in front of them when they see the recommendation, in the same way that advertisers only count an advert once it has been shown to someone, which is what an ad impression measures.

A simple affiliate disclosure checklist

1. Decide which parts of the page earn you something, whether commission, a free product or anything else of value.
2. Put a short label such as "Ad" or "Advertisement" at the top of the post or next to the relevant section.
3. Add one plain sentence near your first affiliate link, such as saying that you earn a commission if someone buys through it.
4. Check it appears on mobile, where the top of the page looks very different.
5. Avoid vague wording, hashtags crowded together and notes that only appear after a click.
6. Re-read the regulator pages now and then, because the guidance gets updated.

Common affiliate disclosure mistakes

• Putting a general note on an About page or in the terms and expecting it to cover every post. The ASA says that's not enough for voucher sites.
• Using wording like "may earn a commission" when you will.
• Assuming a small audience means the rules don't apply. The CMA says they apply regardless of follower count.
• Leaving the whole job to the brand. The ASA says brands share responsibility but affiliates must also make content obviously identifiable.
• Disclosing in a language your reader doesn't use.

Sharing what you know about affiliate disclosure

If you've worked on affiliate programmes and have practical lessons about clear labelling, writing them up helps other site owners stay on the right side of the rules.

Marketers who write about partnerships can see affiliate marketing blogs that accept contributor articles here.

Frequently asked questions

Must small blogs disclose affiliate links?

The CMA says its influencer rules apply no matter how many followers you have. The ASA's guidance on affiliate marketing applies to marketers generally, so a small audience doesn't remove the need to be clear.

Is a disclaimer at the bottom of a post enough?

The ASA says a disclaimer at the bottom of a post is unlikely to be enough. The FTC similarly warns that disclosures at the end of a post are easy to overlook.

What words can I use to label an affiliate link?

The ASA's main example is "Ad", for instance "(Ad)" or "#Ad". The FTC says simple terms such as "ad" or "advertisement" work. Avoid vague labels such as "collab".

Who is responsible for the disclosure, the brand or the affiliate?

The ASA says both the business and the affiliate marketer are responsible under the Code. The brand can't hand over control and ignore the result, and the affiliate must make content obviously identifiable.

Do free products count as a reason to disclose?

Yes. The FTC says free or discounted products count as a relationship that needs disclosing, even if you weren't asked to mention that product.