Microsoft Advertising mandates user consent signals by May 2025

Microsoft Advertising has announced that advertisers must provide user consent signals by May 5, 2025. This requirement, announced on March 31, 2025, marks a significant development in how advertisers must handle user data in regions with strict privacy regulations.

According to Microsoft Advertising, "safeguarding personal information has become crucial not just for regulatory compliance but most importantly for establishing trust with consumers." The company has taken this step as part of its commitment to "putting user privacy at the forefront of our priorities, as we build a web that works for everyone."

What is Consent Mode?

The announcement explains that "Consent Mode is a feature introduced by Microsoft Advertising that enables you to gather insights while respecting user privacy preferences and adhering to privacy regulations." The feature applies to "any client using Universal Event Tracking (UET) on the Microsoft Advertising Platform, as well as the Universal Pixel, Segment, and Conversion pixels within Microsoft Invest, Curate or Monetize."

The technology functions by "adjusting the tracking behavior on Microsoft's tag code based on a parameter called ad_storage." This parameter controls cookie storage on users' devices for advertising purposes, with settings of either "granted" or "denied." When properly implemented, this enables advertisers to "continue tracking conversions and optimizing advertising campaigns without compromising user privacy."

Implementation options

Microsoft has provided three distinct methods for implementing consent signals, stating that "only one of them should be implemented":

1. "Implement Consent Mode on UET (if you are using the Microsoft Advertising Platform), Universal Pixel, Segment or Conversion pixel (if you are using Microsoft Invest, Curate or Monetize)"
2. "Alternatively, you can send us user consent signals using the IAB's Transparency and Consent Framework (TCF), by passing those signals directly in a TCF 2.0 string, or via your CMP of choice."
3. "Finally, if you are using third-party data management tools like Google Tag Manager, integrating Microsoft's Consent Mode is also straightforward."

For technical implementation, Microsoft provides detailed code examples for different scenarios. For instance, to enable TCF v2.0 support with UET tags, advertisers must "add the following code snippet above your UET code on all pages where you have UET tags":

<script>
window.uetq = window.uetq || [];
window.uetq.push('config', 'tcf', { 'enabled' : true });
</script>

For Consent Mode implementation, advertisers can use this example code to set default consent settings:

<script>
!function(e,i){if(!e.pixie){var n=e.pixie=function(e,i,a){n.actionQueue.push({action:e,actionValue:i,params:a})};n.actionQueue=[];
pixie('consent', 'default', { 'ad_storage': 'denied', 'wait_for_update': 1000});
pixie('init', 'REPLACE_WITH_UP_PIXEL_ID');
pixie('event', 'PageView');
</script>

Why it matters

Microsoft emphasizes three key reasons why providing consent signals is important:

1. "Privacy regulations: By enforcing Consent Mode, we help your business comply with privacy laws such as GDPR, avoiding potential fines and penalties."
2. "User trust: Respecting user privacy preferences builds trust with users who are increasingly concerned about how their data is collected and used."
3. "Advertising performance: Even with consent restrictions, you can continue to gather valuable insights to optimize your campaigns, ensuring effective targeting and conversion tracking."

The implications of non-compliance are significant. Microsoft warns that "failing to do so by May 5 will impact your advertising performance for site visits originating from the EEA, UK, and Switzerland."

Effects on tracking and measurement

The technical documentation clarifies how Microsoft Advertising will handle consent signals through the TCF framework. For example:

"Cookies will not be created or used by Microsoft Ads for measurement or personalization" if users do not consent to Purpose 1 (Store and/or access information on a device).

If consent is not provided for Purposes 3 and 4 (Create profiles for personalized advertising and Use profiles to select personalized advertising), "Events are not eligible for ads personalization, and are not used for remarketing lists."

For Purposes 7, 9, and 10 (Measure advertising performance, Understand audiences through statistics, and Develop and improve services), Microsoft states: "Microsoft Advertising requires this purpose for all conversions. If this purpose is not present, Microsoft Ads will not record the conversion."

For advertisers using UET Tag Helper to validate their implementation, the documentation explains how to verify that the correct consent signals are being sent: "The asc parameter within UET events indicates the status of user consent" with possible values of "denied" or "granted."

Supported consent management platforms

Microsoft has ensured compatibility with numerous consent management platforms. According to their documentation, supported CMPs include:

• Cookiebot
• UserCentrics
• Didomi
• Iubenda
• Consent Manager
• Complianz
• OneTrust

Additionally, Google Tag Manager integration is supported, with Microsoft noting: "Although Google Tag Manager (GTM) is not a Consent Management Platform (CMP), it integrates with most CMPs to get consent signals."

Technical implementation details

For Universal Event Tracking users, Microsoft explains how the ad_storage property affects cookie behavior:

When set to "granted" - "First and third-party cookies may be read and written for UET. If no default is set, UET uses granted by default."

When set to "denied" - "First-party cookies are not read nor written for UET. Third-party cookies are not written. Third-party cookies are read-only for fraud and spam purposes—not for advertising purposes."

The implementation requires specific steps, including setting default consent on page load and updating consent settings when users make choices. Microsoft recommends placing "the consent script in your <head> tags so that the Consent Mode is set by default and updated when a user updates their consent settings."

For those using the IAB framework, Microsoft has specific requirements for the TCF string: "UET tags only accept TCF strings that are correctly implemented according to the TCF policies and technical specifications. If your CMP doesn't respond within 500 milliseconds or you see a status of 'error', 'stub', or 'loading', the tag will continue to function without TCF support."

Timeline and preparation

The key dates related to this policy change are:

• July 24, 2023: Microsoft Advertising began supporting IAB TCF v2.0
• March 31, 2025: Announcement of mandatory user consent signals requirement
• May 5, 2025: Enforcement deadline

For advertisers targeting European audiences, the recommendation is clear: "Ensure you provide consent signals on your Microsoft Advertising campaigns as of today, to continue to optimize your advertising efforts while ensuring user preferences are respected."

As Microsoft notes, "As privacy concerns continue to grow, features like Consent Mode will play an essential role in the future of digital advertising." This requirement represents an important shift in balancing advertising effectiveness with user privacy preferences, particularly in regions with strict privacy regulations.

By implementing these consent mechanisms before the deadline, advertisers can maintain their ability to track conversions and optimize campaigns while respecting the increasing importance of user privacy choices in the digital advertising ecosystem.

Timeline

• July 24, 2023: Microsoft Advertising begins supporting IAB TCF v2.0
• March 31, 2025: Microsoft announces mandatory user consent signals requirement
• May 5, 2025: Enforcement deadline for implementing consent signals
• Post-May 2025: Expected impact on campaign performance for non-compliant advertisers targeting the EEA, UK, and Switzerland