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As companies look to unlock new growth frontiers using data-driven strategy, the need to comply with user privacy — including laws relating to the use of cookies — still holds sway.
If you are an ad publisher on Microsoft’s Advertising Platform (MAP) in the European Economic Area (EEA), Switzerland, or the UK, you are now required to implement Microsoft’s Universal Event Tracking (UET) Consent Mode to track, signal, and honor user consent status.
Not complying with this requirement may trigger the suspension of certain UET features that may negatively impact your monetization and conversion tracking. So, how can you implement the UET? And beyond compliance, how is it a valuable addition to your marketing stack? Let’s explore all the details.
Update (March 2025): Microsoft Advertising has announced a new enforcement deadline for its UET (Universal Event Tracking) Consent Mode. Advertisers targeting users in the EEA, UK, and Switzerland must begin sending explicit consent signals to Microsoft by May 5th, 2025, to remain compliant and avoid disruptions in campaign performance. Without proper consent, Microsoft tags may no longer support retargeting or conversion tracking in these regions.
Want to learn more about Microsoft Consent Mode? Check out our webinar where we discussed the technical, strategic, and practical aspects of implementing this framework:
What is Microsoft Universal Event Tracking (UET)?
Launched in July 2023, the Microsoft UET tool helps you track and analyze how users behave on your website after they click on your ad. But to discover how (and why) the tool came about, let’s trace the developments (both law & policy) that have prompted it.
Understanding consent mode for user privacy
The Digital Services Act (DSA), effective January 1, 2024, and the Digital Markets Act (DMA, which became applicable in May 2023, are new regulations for companies in the EEA and the UK.
The DMA is aimed at major tech companies like Alphabet, Amazon, ByteDance, Microsoft, and Apple, known as “digital gatekeepers,” which provide digital services such as search engines, cloud platforms, social media networks, video-sharing sites, and online advertising networks.
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Together with the GDPR, these legislations require organizations in the EEA and the UK to explicitly seek user consent before collecting personal data. In 2020, Alphabet was among the first to comply with these next-level privacy requirements, rolling out the latest iteration of Google Consent Mode. This tool lets advertisers adjust their website's Google (tracking) tags based on user consent.
After the release of the Google Consent Mode V2 in March 2024, new consent parameters (ad_user_data and ad_personalization) emerged, along with two implementation types: Basic and Advanced.
This updated version can also analyze aggregated and anonymized stat using behavioral and conversion modeling from even non-consenting users. In this way, website owners are not left in the dark when a user chooses not to consent.
In the case of Microsoft Advertising, the Consent Mode is a specification in UET that allows Microsoft to receive information about users' consent status (namely, whether or not they choose to share their data). It achieves this first by allowing browser storage access for cookies. Once the cookie data bearing the user's consent status is stored, it sends a signal (using UET tags) to Microsoft.
Why use Microsoft UET?
Another piece of tech that highlights just how privacy can move beyond compliance objectives to help you score big in your marketing strategy, businesses can enhance their marketing using Microsoft’s UET in the following ways:
Data layers
You can also deploy more data layers to add data points (e.g., page category, transaction value, cart items, User ID) you may need to assess for a more robust strategy. With this comprehensive report, you can better understand user preferences, identify which aspects of your site or ads are most effective, and make informed decisions to fine-tune marketing strategy and boost ROI on ad spend.
Remarketing lists
You can create a remarketing list using the insights generated from tracking user activity. This list allows you to target your ads to specific customer segments precisely, ensuring accurate, privacy-safe ads so that only the most relevant audience sees your content.
Doing this not only helps your campaign stay effective but it helps you focus your ad spend on only relevant, potentially converting viewers.
Automate your bidding
If your marketing strategy relies on programmatic/automated bidding, you can simply integrate data from Microsoft ads conversions and general user behavior with Microsoft Ad’s advanced bidding algorithms. This way, you can constantly monitor performance and adjust to optimize your campaign performance and ROI on ad spend.
Consent mode
To help web owners honor user privacy, Microsoft Consent Mode is designed to work seamlessly with Universal Event Tracking (UET). Using this feature, organizations can tailor data practices to each user’s preferences by modifying their UET tags based on whether (or not) a user has consented to having their data collected.
If a user opts out of tracking, for example, Consent Mode ensures the UET tags limit data collection to what is legally permissible, such as gathering anonymous data for basic site functionality. However, if a user provides full consent, the tags can operate in their standard capacity, collecting comprehensive data to optimize advertising efforts.
This approach helps to maintain user trust while balancing user privacy with a legitimate interest in marketing products and services.
How does Microsoft UET consent mode work?
The Universal Event Tracking (UET) tags are at the core of Microsoft UET Consent Mode.
These tags are fragments of code (snippets) that allow you to monitor and measure “conversions.” Remember that conversions, in this case, could mean any specific user activity — think of making a purchase, signing up for an account, or downloading a lead magnet. These tags also generate crucial data that helps assess the performance of ad campaigns.
Consent Mode for Microsoft UET allows you to adjust your UET tags behavior based on user consent on the IAB vendor Microsoft Advertising (IAB ID = 1126). The user consent status is then transferred through a property called ad_storage, which UET tags will be able to process and adjust accordingly:
- ad_storage = granted: both first and third-party cookies will be read and written for UET
- ad_storage = denied: first-party cookies for UET will not be read. In this case, third-party cookies are only read for fraud and spam prevention purposes and not written (or used) for ads.
How can you implement Microsoft UET?
As stated above, it all starts with the (UET) Tag placed on each page of your website.
Organizations can define what action may be interpreted as a conversion (e.g., purchases, sign-ups, or other valuable interactions). The collected user behavior data is then analyzed to inform better ad campaigns, retarget visitors, and fine-tune marketing strategy.
UET integrates with all major tag management systems, including Google Tag Manager, Qubit Opentag, Tealium, Ensighten, Signal, Adobe Dynamic Tag Manager, and Adobe Launch.
In monitoring and applying user consent choices, UET consent mode is managed through the ad_storage property, which needs to be set on each page load and each time the user provides their consent:
- Default consent: When the user visits your webpage where UET tags were placed, a default status for ad_storage. In European Economic Area countries, along with the UK and Switzerland, Microsoft Advertising is gradually enforcing consent mode, where the default value of ad_storage is denied. For most countries, if the ad_storage value is not set, UET will use granted by default.
- Consent update: Once this default setting is implemented, you may include a code on each website page to update consent based on the choice made by users in the cookie consent banner. (You can find examples of such codes in Microsoft Advertising’s official documentation on this topic)
Accordingly, no updates would be necessary if the user has refused access to third-party cookies for advertising purposes. The opposite is also true.
Consent Mode helps advertisers modify how UET Tags function purely based on consent. In this way, ad campaign tracking can only be carried out in line with the user’s consent choices, which they lawfully exercise in Consent Mode.
Is Microsoft UET consent mode mandatory for your business?
The answer depends on your location and the legal requirements for your operations.
If you’re an advertiser in a region like the European Economic Area (EEA), the UK, and Switzerland and targeting customers there, then you need UET to comply with data privacy laws like the GDPR and the e-Privacy Directive (EU Cookie Law).
You may also recall that under EU Cookie Law, you must obtain consent if your website processes users' personal data. Of course, this would exclude the need to seek consent for necessary/essential/functional cookies, which only help the website function optimally and keep it secure.
The variant of cookies that triggers a consent requirement is non-essential cookies. These cookies track personal data such as users’ geolocation, contact details, habits & preferences, demographic data, and other data that may identify a user alone or when paired with other data.
Examples of non-essential cookies include analytic cookies and advertising cookies.
- Analytic cookies track user behavior on a website to provide insights into site performance, user engagement, and navigation patterns. Businesses can then use this powerful insight generated from tracking on-page metrics like page views and time spent on pages to optimize their websites.
- Advertising cookies, on the other hand, create targeted ads by tracking user activity and preferences across websites. These cookies collect personal information to deliver more relevant ads to users, requiring consent under data privacy laws.
Unlike essential cookies, which are necessary for a website to function, non-essential cookies require user consent because they collect personal data. For cookie consent to be validly obtained under the EU Cookie Law, it must be informed, freely given, specific, unambiguous, and revocable.
Why Microsoft is now making it mandatory
New regulations, such as the Digital Service Act and the Digital Markets Act, have increased the need for end-user compliance.
Microsoft Advertising is expected to comply as one of the EU's designated "Gatekeepers," pis along with Amazon, Apple, ByteDance, Meta, and Alphabet. Reflecting the need to include advertisers in the compliance loop, Microsoft has mandated advertisers in the European Economic Area, the UK, and Switzerland to use the UET tag to send user consent signals to UET.
Failing to do so will suspend certain functionalities like conversion tracking and lead to inaccurate data. If user consent isn't communicated to UET, you may lose track of valuable data, which may limit your ability to optimize, create new audience segments, or leverage automatic bidding.
Given that marketing strategies rise and fall with data quality, incomplete conversion data will surely adversely impact your ad campaign’s performance.
How to get started with Universal Event Tracking (UET) consent mode and Didomi
To neatly implement the Microsoft UET, you won’t find a better tool than a Consent Management Platform. The role of your CMP here would be to handle consent requests and pass the UET consent signals to UET based on the user’s chosen consent.
Didomi supports major privacy frameworks, and that includes Microsot UET consent mode. Learn more about it and how to activate it in the Didomi Console by checking our Microsoft consent mode documentation, and get in touch with our team if you have any questions or to discuss your data privacy and compliance challenges:
Frequently Asked Questions (FAQ)
What is Microsoft UET Consent Mode?
Microsoft UET Consent Mode lets organizations adjust their use of UET tags based on users' consent preferences. It ensures compliance with data privacy laws like GDPR and the ePrivacy Directive while respecting user choices.
What websites support UET?
UET works well with major website platforms, such as Bigcommerce, Shopify, Wordpress.com, and Wix.
Is it compulsory for me to use a CMP to implement the Microsoft UET?
No. However, a CMP cookie consent banner provides you with a far more solid legal footing. You can seek user consent in a clear manner that helps them express their consent choices even before they start using the website.
How does a CMP implement the Microsoft UET?
Using the Transparency and Consent Framework (TCF) string, CMPs first record user consent choices (granted or denied). This data is then sent to Microsoft Advertising, where UET tags adjust their tracking based on the user's consent.
How long does Microsoft UET keep my data?
Microsoft UET retains your data for a set period, which can vary depending on the specific policies and your use case. Generally, user data is stored for up to 390 days, but other datasets, like IP addresses and the Microsoft Cookie itself, are kept for up to 13 months.
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