Microsoft Consent Mode, also called UET Consent Mode, is a Microsoft Advertising feature. It adjusts how the Universal Event Tracking (UET) tag reads and writes cookies based on a visitor's consent choice. It keeps Microsoft Ads measurement working while respecting privacy rules in the EEA, UK, and Switzerland.
This guide covers how the ad_storage signal works and how Basic and Advanced setup differ. It also covers the May 5, 2025 requirement and how Microsoft's consent mode differs from Google's and from Clarity's own consent system.
What Is Microsoft Consent Mode?
Microsoft Consent Mode is Microsoft Advertising's own implementation of consent signaling for its Universal Event Tracking (UET) tag. Microsoft's help documentation states it plainly: "UET Consent Mode lets you adjust UET cookie access based on the consent status of your users". The feature governs whether UET can read and write first-party cookies, set by your own domain, and third-party cookies, set by Microsoft Advertising at Bing.com.
Microsoft Advertising introduced Consent Mode so advertisers keep collecting conversion and remarketing data without ignoring a visitor's privacy choice. UET runs on every page of a site. Without a consent signal, it has no way to know whether a visitor has agreed to tracking. Microsoft's own product positioning calls it a feature "that enables you to gather insights while respecting user privacy preferences and adhering to privacy regulations".
For sites with traffic from the European Economic Area, the UK, or Switzerland, Microsoft now requires this signal (covered below). For every other visitor, UET defaults to granted unless you configure it otherwise.
What Is UET (Universal Event Tracking)?
UET is Microsoft Advertising's single website tracking tag. Microsoft describes it as a tool that "records what customers do on your website". Advertisers use that record to track conversion goals, build remarketing audiences, and feed automated bidding. You add one UET tag to every page once, and Microsoft Advertising collects the data behind the scenes.
UET predates Consent Mode by years. Consent Mode sits on top of the existing UET tag as a privacy control layer, not a replacement tag. A site that already has UET installed adds Consent Mode by adjusting how that same tag behaves, not by installing anything new.
The UET tag serves three core functions.
- Conversion tracking, recording when a visitor completes a goal such as a purchase or signup
- Remarketing audiences, building visitor lists to retarget with future ads
- Automated bidding, feeding Microsoft's bid strategies with the conversion data the tag collects
How Does Microsoft Consent Mode Work?
When a visitor makes a choice in your cookie banner, your consent management platform passes that choice to Microsoft as a consent signal. The UET tag reads that signal and stores its cookies normally when granted, or holds back when denied. It checks the signal fresh on every page load, for as long as the consent choice applies.
Microsoft's own documentation frames this as adjusting "the tracking behavior on Microsoft's tag code based on a parameter called ad_storage". The mechanism runs through two calls. A default call sets the starting state before a visitor interacts with the banner. An update call fires the moment they accept or reject, and UET reads whichever state is active on each page load.
The ad_storage Signal: Granted vs Denied
The ad_storage signal is Microsoft's single consent parameter for UET, and its two values control cookie behavior with more precision than a blanket on/off switch.
ad_storage value | What the UET tag does |
|---|---|
granted | First-party and third-party cookies may be read and written for UET. This is the default when no value is set. |
denied | First-party cookies are not read or written at all. Third-party cookies are not written, but they may still be read for fraud and spam prevention, never for advertising. |
That fraud-prevention carve-out is easy to miss. Denied does not mean UET goes completely silent. Microsoft's documentation is explicit on this point. Third-party cookies stay read-only for fraud and spam checks even when a visitor declines, a narrower exception than most explainers describe.
Microsoft primarily reads this one parameter, unlike Google Consent Mode, which uses the four consent-mode signals (ad_storage, analytics_storage, ad_user_data, and ad_personalization) across its own products.
How the Consent Signal Reaches Microsoft
The consent choice travels from your banner to Microsoft on the actual tracking request, carried by a request-level parameter called asc. Microsoft's own UET documentation confirms it directly: "the asc parameter within UET events indicates the status of user consent," reading either granted or denied.
The signal moves through a short chain:
- A visitor makes a choice in your cookie banner
- Your consent management platform (CMP) updates the consent state
- The UET tag reads the current ad_storage value
- Every UET request afterward carries that value as the asc parameter
You can watch this happen in your browser's network requests. Microsoft's own verification tools, covered in the FAQs below, confirm it too.
Basic vs Advanced Consent Mode
Basic and Advanced Consent Mode differ in when the UET tag fires and how much data reaches Microsoft before a visitor makes a choice.
| Attribute | Basic Consent Mode | Advanced Consent Mode |
|---|---|---|
| Tag loading | Blocked until the visitor grants consent | Loads immediately, with consent defaulted to denied |
| Data collection | None sent before consent | Anonymized, identifier-free data collected and aggregated before modeling |
| Consent status | Set only after the visitor grants consent | Defaults to denied, then updates on the visitor's actual choice |
| Data modeling | Generic, category-level modeling | More precise modeling tailored to the advertiser |
Microsoft recommends Advanced Consent Mode as its technical best practice, because it closes the measurement gap Basic mode leaves behind. When a visitor declines under Advanced mode, no cookies or personal identifiers reach Microsoft. Microsoft's own description confirms it: "no advertising identifiers are attached to requests" when consent is denied.
Advanced Consent Mode then applies conversion modeling. Microsoft describes it as intelligent modeling that "[uses] aggregate trends from existing data to estimate conversions that would otherwise be lost". Basic mode has no modeling at all, so its reported conversion drop after a consent decline looks larger by comparison. Conversion modeling works the same way across Microsoft's and Google's platforms: it estimates outcomes from aggregate patterns, not individual identifiers.
Is Microsoft Consent Mode Required? The May 5, 2025 Rule
Yes, if you run Microsoft Advertising and receive traffic from the EEA, the UK, or Switzerland. Microsoft required advertisers to provide user consent signals by May 5, 2025. Sites that skip it lose ad performance, conversion attribution, and remarketing audiences for visitors from those regions.
Microsoft's own blog states the mandate directly: it is "enforcing the explicit provision of user consent signals by May 5, 2025". The consequence is equally direct. Failing to meet the deadline "will impact your advertising performance for site visits originating from the EEA, UK, and Switzerland". The requirement traces to the EU's ePrivacy Directive and the GDPR. Those are the same legal drivers behind Google's own consent mandate.
Without a granted ad_storage value, skipping the signal degrades three things.
- Conversion measurement, since UET cannot confirm the outcome without a consent state
- Conversion attribution, since Microsoft cannot connect the ad click to the result
- Remarketing audiences, since UET cannot build or update visitor lists without consent
US-only advertisers with no EEA, UK, or Swiss traffic are not covered by this specific rule. That does not remove every consent obligation, since opt-in versus opt-out models still differ by region for other privacy laws.
How to Set Up Microsoft Consent Mode
Microsoft supports three routes to provide the required consent signal, and most sites use whichever one their existing consent setup already supports.
- A supported consent management platform. Microsoft lists more than 20 named CMPs that integrate directly, so the banner sends the signal automatically once configured.
- The IAB Transparency and Consent Framework (TCF). Sites already passing a TCF 2.0 string can rely on that framework instead of a separate implementation.
- Manual or Google Tag Manager implementation. Advertisers set the ad_storage parameter directly in code, or through Microsoft's official UET template in GTM.
Microsoft also reads consent signals automatically from any standard consent solution and cookie banner. This works without a direct implementation, unless that auto-reading is explicitly disabled. For the exact code, GTM template configuration, and CMP-specific instructions, follow our full setup guide.
Microsoft Consent Mode vs Google Consent Mode
Microsoft Consent Mode and Google Consent Mode share the same core signal but differ in scope and complexity.
| Aspect | Google Consent Mode | Microsoft Consent Mode |
|---|---|---|
| Tags covered | Google Analytics and Google Ads | UET (Microsoft Advertising) only |
| Signals used | Four (ad_storage, analytics_storage, ad_user_data, ad_personalization) | One (ad_storage) |
| Typical complexity | Broader CMP ecosystem, more signals to configure | Simpler, ads-focused setup |
| Shared parameter | ad_storage | ad_storage |
Both platforms standardize on ad_storage. A single consent management platform that sends this signal correctly can drive both Google's and Microsoft's tags from the same visitor choice. Google's version covers more ground, since Analytics and Ads both read its four signals. Microsoft's stays narrower and centers entirely on UET, which is also why its setup is generally the faster one to configure.
Microsoft Consent Mode vs Microsoft Clarity Consent Mode
Microsoft Consent Mode and Microsoft Clarity's Consent Mode are two separate systems, even though both carry Microsoft's name. "Microsoft Consent Mode" usually means UET consent signaling for Microsoft Advertising. Microsoft Clarity, the free analytics and heatmap tool, runs its own, unrelated consent system through a consentv2 API.
Clarity's own documentation confirms the split: "consentv2 is the latest and recommended method for passing user cookie consent status to Clarity". Its syntax takes two parameters, ad_Storage and analytics_Storage, both required. That is unlike UET's single ad_storage signal. A site running both UET and Clarity must signal consent to each system separately, since setting one does not configure the other.
The two surfaces also enforce their EEA/UK/Switzerland requirement on different dates. UET Consent Mode became mandatory May 5, 2025. Clarity enforces its own consent requirement starting October 31, 2025, a full six months later. A site compliant on one deadline is not automatically compliant on the other.
| Surface | What it is | Consent parameter |
|---|---|---|
| UET Consent Mode | Microsoft Advertising's ad-tracking consent signal | ad_storage (one value) |
| Clarity Consent Mode | Microsoft Clarity's session-recording consent signal | ad_Storage and analytics_Storage (both required) |
How Consently Sends Microsoft Consent Signals
Consently's cookie banner captures a visitor's consent choice and sends the ad_storage signal Microsoft's UET tag reads. It sends the signals Google requires at the same time, so both platforms behave correctly without hand-coded tag logic.
I configured Consently once, and it kept sending both Google's and Microsoft's consent parameters from the same banner choice. Neither platform needed a separate integration step. That matters most for the practitioners who report conversion tracking breaking after a consent-mode change. The fix is almost always a banner that captures the choice but never relays it correctly to the ad platform. Consently's job is making sure that relay never drops.
Consently also applies region-based templates automatically. EEA, UK, and Swiss visitors see an opt-in banner, while other visitors see the region's appropriate model. Consently is not on Microsoft's own named list of directly integrated CMPs. It sends the signal through the cookie-banner and standard-consent-solution path Microsoft's own documentation supports, rather than through a listed direct integration.
Try Consently free to send Microsoft and Google consent signals from one banner, no credit card required.
FAQs
What is Microsoft Consent Mode in simple terms?
Microsoft Consent Mode is a feature that lets Microsoft Advertising's UET tag check a visitor's cookie choice before storing or reading cookies. Granted lets it track normally; denied blocks first-party cookies and limits third-party cookies to fraud checks only.
Is Microsoft Consent Mode the same as Google Consent Mode?
No, but they share the ad_storage signal. Google's version covers four signals across Analytics and Ads; Microsoft's covers one signal for UET alone. A single CMP sending ad_storage correctly can satisfy both at once.
What happens if I do not set up Microsoft Consent Mode?
For EEA, UK, or Swiss traffic, skipping it degrades ad performance, conversion attribution, and remarketing audience building, per Microsoft's May 5, 2025 requirement. Outside those regions, UET defaults to granted and keeps tracking as before.
Does Microsoft Consent Mode work without a cookie banner?
No. A cookie banner or consent management platform is what captures the visitor's choice in the first place. Consent Mode only relays that choice to UET; it has no way to collect consent on its own.
How do I check if UET Consent Mode is working?
Use the UET Tag Helper browser extension for Edge or Chrome. It inspects the asc parameter on UET requests, which should read granted or denied correctly. Microsoft's UET Dashboard also shows a Consent status column per event type. It reads Healthy when more than 75% of recent events carry a valid signal, Moderate below that, or Missing at zero.
Is UET Consent Mode free?
Yes. Consent Mode is part of UET and Microsoft Advertising at no extra cost. You still need a cookie banner or consent management platform to capture and send the actual consent choice.
Does Microsoft Clarity need Consent Mode too?
Yes, separately. Clarity runs its own consentv2 API with its own required parameters. It also enforces its own deadline, October 31, 2025, for EEA, UK, and Swiss traffic, distinct from UET's Consent Mode.
