Amazon Consent Signal: What It Is and How to Set It Up with Kukie

What Is Amazon Consent Signal?

If you run Amazon Ads targeting European audiences, your campaigns need a valid consent signal - or you risk losing ad delivery, targeting, and measurement. Since 7 February 2025, Amazon has required all advertisers who transmit personal data from UK or EEA users to send a verified consent signal alongside that data.

Amazon Consent Signal (ACS) is Amazon's proprietary consent framework for advertising. It works in a similar way to Google Consent Mode v2, but is built specifically for the Amazon Ads ecosystem - covering Amazon DSP, Amazon Marketing Cloud, and Ads Data Manager.

ACS uses two parameters to communicate a visitor's privacy choices to Amazon:

• amzn_user_data - whether the user has consented to Amazon processing personal data for advertising purposes

• amzn_ad_storage - whether the user has given consent for Amazon to read or write advertising cookies on their device

Both parameters accept either GRANTED or DENIED as values. They map directly to the marketing cookies category in most consent management platforms.

ACS or IAB TCF - Which Do You Need?

Amazon accepts two methods for transmitting consent: ACS or the IAB Transparency and Consent Framework (TCF). You do not need both.

The key difference is scope. TCF is an industry-wide standard that encodes consent for dozens of vendors and purposes into a single TC String. ACS is Amazon-specific and uses a simpler first-party cookie format. If you already run TCF on your site and Amazon is included as a vendor, your consent obligations to Amazon may already be met. If you do not use TCF, ACS is the straightforward alternative.

Why ACS Matters for Your Business

Running Amazon Ads without a valid consent signal does not just create a compliance risk. It directly affects campaign performance.

Without ACS, Amazon cannot process personal data for ad personalisation or measurement on behalf of UK and EEA users. That means broken conversion attribution, reduced audience targeting, and gaps in your campaign reporting. If you rely on Amazon DSP or Amazon Marketing Cloud for programmatic advertising, those gaps translate to wasted spend and unreliable data.

With a valid consent signal in place, your campaigns continue to run as expected for users who grant consent. Conversion modelling stays accurate. Attribution data flows through. You meet your obligations under the GDPR and ePrivacy Directive without manually wiring up consent logic.

How the amzn_consent Cookie Works

When a visitor arrives on your site, your consent management platform (CMP) displays a cookie banner. The visitor makes a choice - accept, reject, or customise.

Your CMP then sets a first-party cookie called amzn_consent on your domain. This cookie contains a small JSON object with four fields:

• geo.countryCode - the ISO 3166 country code where consent was recorded (e.g. GB, DE, FR)

• amazonConsentFormat.amznAdStorage - GRANTED or DENIED

• amazonConsentFormat.amznUserData - GRANTED or DENIED

• timestamp - ISO 8601 timestamp of when consent was recorded

Amazon Ads tags on your site read this cookie automatically. No additional JavaScript calls or API integrations are needed on your end. The cookie approach differs from Google Consent Mode, which relies on gtag('consent', 'update', ...) calls in JavaScript.

One technical note: because the amzn_consent cookie contains JSON, some Web Application Firewalls (WAFs) may flag or block it. If you notice the cookie is not being set, check your WAF rules and add an exception for this cookie name.

Setting Up ACS with Kukie

Kukie has built-in support for Amazon Consent Signal. The setup takes less than a minute and requires no code changes.

Step-by-step

1. Log in to your Kukie dashboard at app.kukie.io

2. Go to Integrations in the left sidebar

3. Find Amazon Consent Signal and toggle it on

4. Click Save

That is it. Kukie automatically captures your visitor's consent choice and country, then writes the amzn_consent cookie with the correct ACS format. When a visitor grants marketing consent, both amzn_user_data and amzn_ad_storage are set to GRANTED. When they decline, both values are set to DENIED.

ACS integration is available on Kukie's Pro and Business plans. For detailed configuration options, see the ACS integration guide in the Help Centre.

Testing Your ACS Integration

After enabling ACS, verify it is working correctly using your browser's developer tools.

Check the amzn_consent Cookie

1. Open your website in Chrome or Firefox

2. Open DevTools (F12 or right-click and select Inspect)

3. Go to the Application tab (Chrome) or Storage tab (Firefox)

4. Under Cookies, select your domain

5. Search for amzn_consent

Accept marketing cookies on the banner and refresh the cookie list. You should see a JSON value with amznAdStorage and amznUserData both set to GRANTED, along with a valid country code and timestamp.

Then clear your cookies and reload the page. This time, reject marketing cookies. The amzn_consent cookie should now show DENIED for both parameters. If the cookie does not appear at all, check whether a WAF or content security policy is interfering.

You can also verify the country code field. If you are testing from the UK, the geo.countryCode value should read GB. For visitors in Germany it would show DE, for France FR, and so on. This country code is what tells Amazon which jurisdiction's consent rules apply to that particular visitor.

ACS Alongside Other Consent Signals

Most websites run advertising from more than one platform. You might use Google Ads, Meta Pixel, Microsoft Advertising, and Amazon DSP on the same site. Each platform has its own consent signal format, and each operates independently.

Kukie handles all of these from a single dashboard. You can enable ACS, Google Consent Mode, Microsoft UET Consent Mode, and other integrations simultaneously. They do not conflict with each other - each integration writes its own signal based on the same visitor consent choice.

This is particularly useful for ecommerce sites that rely on multiple ad platforms for retargeting and attribution. Rather than maintaining separate consent implementations, Kukie's script blocking and consent signal features centralise everything.

For sites that also need to meet GDPR cookie consent requirements across different regions, Kukie's geo-detection and region rules ensure the correct consent model is applied based on where the visitor is located.

The Enforcement Context

Amazon's consent signal requirement did not appear in a vacuum. European data protection authorities have been increasingly focused on advertising consent practices.

Amazon itself faced a landmark enforcement action when Luxembourg's CNPD issued a EUR 746 million fine in July 2021 for processing personal data for targeted advertising without valid, freely given consent. While the Luxembourg Administrative Court annulled that specific decision in March 2026 and referred it back to the CNPD for re-analysis, the underlying principle was upheld: using personal data for ad targeting requires proper consent under the GDPR.

The ACS requirement is Amazon's response to this regulatory environment. By mandating that advertisers transmit verified consent signals, Amazon shifts part of the compliance burden to publishers and advertisers. If you are sharing data with Amazon Ads from UK or EEA users, the responsibility to collect and transmit valid consent sits with you.

Frequently Asked Questions

Set Up Amazon Consent Signal Today

If you run Amazon Ads in the UK or EEA, ACS is not optional. Kukie makes the setup automatic - enable the integration, save, and your consent signals start flowing. No code changes, no developer time, no risk of misconfigured cookies.

Start Free - Add ACS to Your Site