Do Affiliate Cookies Require Consent? Or Are Affiliate Cookies Strictly Necessary?

Affiliate cookies live in a curious gray area of privacy law. Under the GDPR and ePrivacy Directive, all cookies need user consent unless they're deemed "strictly necessary," which begs the question: where do affiliate cookies fall?

The short answer is that most affiliate cookies do require consent. That said, if an affiliate cookie directly enables a transaction specifically requested by a user (like a cashback or loyalty program), it can qualify as strictly necessary.

"Strictly necessary" cookies would only apply to user-requested services, like cashback/loyalty programs, and not regular affiliate links.

Even so, the line between necessary and non-essential isn't always clear. And with regulators paying closer attention to cookie practices, understanding where your affiliate program stands is vital. This article discusses when affiliate cookies need consent, when they don't, and how to keep your practices legally compliant.

What Are Affiliate Cookies and Why Do They Raise Legal Concerns?

Affiliate cookies are small tracking files dropped on users' browsers when they click an affiliate link. These files act as digital breadcrumbs that tell merchants which affiliate partner sent a customer their way.

Each cookie contains a unique affiliate ID. When someone clicks a link (say from a blog or a social media post), they're taken to the merchant's site, and that cookie tags along. If the person makes a purchase or signs up, the cookie tells the system which affiliate should earn the commission for the sale.

The cookie's lifespan varies depending on the affiliate program. Some cookies last for 24 hours, while others can remain for up to 30 days. If the cookie expires before the user converts, the affiliate might miss out on commissions, as merchants typically rely on these cookies to attribute sales.

Here's how Amazon explains the purpose and duration of affiliate links:

And here's an example of an affiliate cookie notice from Selfridges' cookie Privacy and Cookie Policies:

It's worth noting that affiliate cookies don't store personal data (i.e., names, email addresses, phone numbers, etc.), nor are they inherently used to spy on anyone. They exist purely for tracking clicks and conversions. Nonetheless, their "tracking" nature places them in the crosshairs of privacy laws and regulatory authorities.

How Do Privacy Laws Regulate Cookies and Consent? (A Quick Legal Primer)

The most relevant privacy laws to consider for our purposes are the EU's General Data Protection Regulation (GDPR) and the ePrivacy Directive. In the United Kingdom, the UK GDPR and the Privacy and Electronic Communications Regulations (PECR) mirror much of the same logic as their EU counterparts.

Here's the core idea: Cookies themselves aren't considered personal data. But they can collect or connect to it. If a cookie tracks user behavior or stores identifiers (e.g., IP address) that can link back to a person, it contains personal data and, therefore, falls under the GDPR's scope.

This triggers broader data protection requirements under the GDPR, including the need for lawful processing. Consent isn't always required, as it's just one of several lawful bases under the GDPR.

Here's precisely what the GDPR says about cookies in Recital 30:

"Natural persons may be associated with online identifiers provided by their devices, applications, tools and protocols, such as internet protocol addresses, cookie identifiers, or other identifiers such as radio frequency identification tags. This may leave traces which, in particular when combined with unique identifiers and other information received by the servers, may be used to create profiles of the natural persons and identify them."

Importantly, the GDPR doesn't actually govern cookie consent. That role belongs to the ePrivacy Directive (and PECR in the UK). This law is more targeted at cookies. It requires websites to get informed consent before placing any cookie on users' devices unless the cookie is "strictly necessary" to provide a service the user has actively requested.

Here's the legal text as presented in Article 5 (3) of the ePrivacy Directive 2009 amendment:

For example:

• A session cookie that remembers what’s in your shopping cart? No consent needed.
• A cookie that tracks visits for marketing purposes (including affiliate programs)? Consent is usually required.

The bottom line: if a cookie isn't essential for the basic function of the site (or tied to a user-requested service), it needs consent under the ePrivacy Directive. The GDPR only applies later if the cookie collects some form of personal data.

Do Affiliate Cookies Require User Consent?

Yes, most affiliate cookies require explicit consent before they can be placed on someone's device. This is because affiliate cookies typically act as measurement or targeting tools.

They track user behavior (clicks, conversions) to determine payouts, often across third-party networks. As a result, both EU and UK privacy laws consider them either "performance" or "advertising" cookies, depending on how exactly they're used.

Case in point, the International Chamber of Commerce (ICC) UK Cookie Guide explicitly classifies standard affiliate tracking under performance cookies. Note that if these cookies are used to retarget users, they effectively become targeting or advertising cookies:

Since standard affiliate cookies aren't strictly necessary for providing user-requested services, they (like other non-essential cookies) need explicit consent to be legally valid under EU and UK jurisdictions.

Here's the French data protection authority (CNIL) backing this sentiment in its amended cookie guidelines and recommendations FAQ:

Some affiliate marketers have tried arguing that seeking consent hurts conversion rates and can lead to revenue leakages for affiliate publishers due to difficulty in attributing sales. Regulators, however, remain unconvinced by these arguments.

It's important to note that just mentioning affiliate cookies in your Privacy Policy or Cookies Policy isn't compliant in jurisdictions like the EU and UK. You need active, specific consent before placing these cookies. In practice, the consent must be:

• Freely given (no pre-ticked boxes)
• Specific to affiliate tracking
• Informed (explaining what the cookies do)
• Unambiguous (clear affirmative action required)
• Withdrawable (just as easily as it was given)

Who's Responsible for Affiliate Cookie Consent?

Both merchants and affiliates share responsibility for cookie consent, but the website placing the cookie carries the primary legal burden. In practice, that means publishers (like blogs, media sites, and influencers) are responsible for getting affiliate cookie consent.

For standard affiliate programs like Amazon Associates, this creates a clear division of duties. When you place an Amazon affiliate link on your blog or website, you're responsible for getting consent before the tracking cookie is set.

Amazon's Associate Program Policies explicitly require affiliates to comply with all applicable laws, which, as we've established, includes getting cookie consent when necessary:

This responsibility exists because the cookie is placed when users click your link, before they even reach Amazon's website. The same applies to most affiliate networks like Webgains, Awin, etc.

So, while brands and affiliate networks do have their own legal and privacy obligations, the consent burden lies with whoever triggers the affiliate cookie through their website or app.

Are There Exceptions to Consent Requirements for Affiliate Cookies?

Yes, but only in very specific cases. Regulatory authorities like the UK's Information Commissioner's Office (ICO) and France's data protection authority (CNIL) have clarified that some affiliate cookies can be exempt from consent requirements. But this exemption is narrow and doesn't apply to most typical affiliate setups.

So, when exactly does the exception apply?

Cashback, loyalty, and points-based programs are the main examples. These are services where a user intentionally signs up to earn a reward (like getting cash back or points) by shopping through a specific partner site.

As of October 2024, the ICO stated that consent isn't required for these reward-based affiliate cookies since they're strictly necessary to track purchases so rewards can be issued:

The logic is that the user has clearly requested this service. The cookie is there to make that specific service work, not to build a profile, track for ads, or share data for unrelated purposes. Without it, the cashback service simply couldn't work.

France's data protection authority (CNIL) echoes this sentiment. In April 2022, the commission decided that affiliate cookies used for cashback or rewards purposes can be exempt from consent requirements, as long as they're essential to deliver the service users signed up for:

Keep in mind that the cashback and rewards exception has clear boundaries. It only applies when:

• The user has deliberately joined the loyalty/cashback program
• The cookie’s primary purpose is to enable that specific service
• The tracking is limited to what’s necessary for the service to work

Importantly, the strictly necessary exemption doesn't extend to typical affiliate links, like those on blogs, review sites, or influencer pages.

In these cases, users haven't actively requested a service. They've just clicked a link. The tracking primarily serves the affiliate and merchant, not the user. And that makes consent necessary.

How to Legally Use Affiliate Cookies

Using affiliate cookies legally can be broadly broken into three requirements: get proper consent, be transparent, and explore alternatives where possible. Here's how to implement each:

Provide a clear, user-friendly consent banner

Obtaining valid consent for affiliate cookies is the most important legal requirement for affiliate publishers. Even if your affiliate cookies don't fall under the scope of the GDPR, it's widely considered a best practice to keep your consent mechanism GDPR-compliant (if only for caution's sake).

In practice, this means:

• No cookie walls: Don't block access to your site until users accept all cookies
• No pre-ticked boxes: Users must actively select affiliate cookies
• Clear language: Explain what affiliate cookies do in plain terms
• Granular choices: Let users accept some cookies and reject others
• Equal prominence: "Accept" and "Reject" buttons should look similar and be equally accessible

Some publishers combine affiliate cookies with categories like "performance," "analytics," or "advertising" cookies, but it's debatable whether these practices are legally compliant, especially since the GDPR requires consent to be specific.

A much better alternative is to create a specific "Affiliate Cookies" category so there's no doubt about their purpose. To drive home that point, here's an example of a GDPR-compliant cookie consent banner from Selfridges:

Note how the affiliate cookie consent toggle is off by default. To provide valid consent under EU and UK privacy laws, users would have to flip the toggle themselves.

As for your cookie text, consider clear, simple phrasing like:

"Affiliate cookies help us track when you click through to partner sites. If you make a purchase, we may earn a commission. These cookies don't contain personal information but do create a unique identifier to track conversions."

Be transparent about your cookie practices

Transparency is a staple of modern privacy laws, including the GDPR and ePrivacy Directive. Being transparent about your cookie practices means outlining every relevant information about how you handle cookies in your Privacy Policy or Cookies Policy, including but not limited to:

• Which cookies (including affiliate cookies) you use and their purpose
• What type of data these cookies collect (if any)
• Who you share data with (e.g., affiliate networks or ad partners)
• How long your affiliate cookies will last
• Your consent collection method (if applicable)
• Your process for honoring rejected cookies

Here's a good example of these disclosures from VistaThink's Privacy Policy:

Even if your affiliate program falls under the strictly necessary exemption (i.e., cashback or loyalty programs), it's important to clearly explain why these cookies are strictly necessary for the program to work in your Privacy or Cookies Policy.

Consider other alternatives to third-party affiliate tracking

Third-party cookies and similar trackers have faced growing legal and browser restrictions, and affiliate tracking often relies on them by default. That's because most affiliate networks or merchants are considered third parties on a publisher's site.

To reduce risk and keep tracking compliant, many affiliate programs now offer alternatives that don't rely on browser-based third-party cookies, such as:

• Server-side tracking, where click data is logged securely on your backend instead of through a browser cookie
• First-party cookies, which are set by your own domain rather than a third party

These approaches may still require consent, but they generally allow for better data governance. Regulators also tend to view them more favorably because they limit unnecessary third-party data sharing. Some networks, like Rakuten, now support server-to-server tracking as a standard option.

If your affiliate program still relies only on third-party cookies, it's worth asking about privacy-friendly alternatives (or exploring platforms that offer them).

What Happens If You Don't Get Consent for Affiliate Cookies?

Violating consent requirements under the ePrivacy Directive (and UK PECR) means risking formal warnings, investigations, and fines, even if you're just a small publisher. The GDPR may also apply if any personal data is involved, in which case fines can go as high as €20 million or 4% of your global annual revenue, whichever is higher.

Enforcement has intensified in recent years, with regulators specifically targeting dark patterns, "consent fatigue" tricks, cookie walls, and similar practices. Case in point:

• France's CNIL fined Facebook €60 million in 2022 for making cookie rejection harder than acceptance (a common dark pattern).
• The UK's ICO recently launched a cookie compliance initiative to review the top 1,000 UK websites.
• Smaller publishers have also faced reprimands, especially for using third-party cookies without proper banners.

Beyond fines, users increasingly distrust sites with sketchy consent practices, which can tank conversion rates. Plus, merchants may drop affiliates whose traffic triggers compliance complaints.

Most enforcement proceedings begin with warnings rather than immediate fines, but regulators are growing less patient with basic consent violations.

Summary

Most affiliate cookies require explicit user consent before you can legally use them under EU and UK privacy laws. The only exception is for cashback and loyalty programs, where tracking is essential to deliver what users specifically signed up for.

Compliance isn't optional. Regulators increasingly target cookie consent violations with fines and enforcement actions that can hurt both your wallet and reputation.

To stay on the right side of privacy laws like the GDPR and ePrivacy Directive (or UK PECR), remember to:

• Audit your current affiliate tracking setup
• Implement a proper cookie consent mechanism with clear language
• Explore server-side or first-party tracking alternatives where possible
• Be completely transparent about your cookie practices