What happens to your Bing Ads data when a user declines cookies? If you run Microsoft Advertising campaigns in the EEA, UK, or Switzerland, that question shapes your conversion reports directly. The answer lies in how Microsoft Consent Mode v2 works with your UET tag. It keeps measurement signals active even when users opt out of tracking.
Without consent mode, a declined cookie means a completely invisible user. No event fires and no attribution is recorded. Your campaign data shows fewer conversions than your business actually generated. Microsoft consent mode v2 addresses this with a smarter approach to data collection. It respects each user’s choice while preserving as much measurement signal as the law permits.
This blog explains exactly how Microsoft consent mode v2 improves Bing Ads tracking. We cover each step, from when a visitor lands on your site to when Microsoft processes a conversion and updates your campaign reports.
The UET tag controls what data Microsoft Advertising receives, and consent mode v2 determines precisely how it behaves for every user who visits your site.
The UET tag reads a single binary parameter called ad_storage. This value is either granted or denied, based on what the visitor chose on your consent banner. When ad_storage is set to granted, the tag operates in full tracking mode. It sends complete event data with cookies placed on the user’s device. When it is set to denied, the tag shifts immediately into restricted mode. It prevents any personal data from being stored or sent to Microsoft.
This parameter is not something your team sets manually for each user. A consent management platform integrated with your site sends the appropriate signal to the UET tag in real time. The tag reads the incoming signal and adjusts before any data leaves the user’s browser.
When a visitor accepts cookies on your consent banner, the ad_storage parameter is set to granted. The UET tag fires at full capacity. It places cookies on the device, captures all relevant conversion events such as purchases, form completions, and sign-ups, and sends the data to Microsoft Advertising. Attribution is tied correctly to the specific ad click that drove the visit. This is the standard tracking state most advertisers are already familiar with.
Consent mode v2 does not change how this standard mode works. It simply ensures the tag only operates at full capacity when the user has actively agreed. The tag does not assume consent. It waits for a clear signal before proceeding.
When a visitor declines cookies, the ad_storage parameter is set to denied. The UET tag does not shut down entirely. Instead, it sends a cookieless ping that carries no personal identifiers and places no cookies on the user’s device. It signals to Microsoft that a visit occurred without disclosing who the visitor was. This restricted mode is what makes Microsoft UET Consent Mode fundamentally different from simply switching tracking off when consent is refused. The tag stays active but operates strictly within the boundary defined by the user’s choice.
When a user declines consent, the UET tag fires a lightweight signal that records the visit without capturing any data that could be traced back to an individual.
Every UET event includes a parameter called asc, which stands for ad storage consent. When ad_storage is granted, this parameter carries the value G. When it is denied, it carries the value D. Microsoft’s servers read this value and handle the associated data accordingly.
A ping marked with asc=D tells Microsoft a visit occurred on your site without identifying who that visitor was or linking them to a specific ad click.
Here is what a denied-consent cookieless ping includes and what it excludes:
Even without personal identifiers, cookieless pings contribute to your campaign data in two meaningful ways. First, they give Microsoft contextual signals such as device type, time of session, and broad location category. Second, they feed into Microsoft’s conversion modelling system.
This system uses patterns from these anonymised signals to estimate what would have been recorded under full consent. A user who declined tracking is not simply invisible. Their visit leaves a trace that Microsoft processes at an aggregate level.
This means your data gap from denied-consent users is narrower than it would be without consent mode. The balance between user consent and campaign measurement is maintained without crossing any regulatory boundary.
Cookieless pings define a clear boundary between what advertisers can measure and what users have declined to share. The visitor’s decision is fully respected. No personal data is stored, no profile is created, and no interest-based targeting is applied to that session.
At the same time, the advertiser does not lose all visibility. The signal exists and is processed by Microsoft in aggregate, stripped of everything that could identify the individual behind it.
This approach allows Microsoft’s measurement system to function partially in declined-consent environments. That partial function is the core mechanism behind how Microsoft consent mode v2 improves Bing Ads tracking at the data collection level.
Microsoft uses aggregated anonymised signals to estimate conversions that cannot be directly attributed when users decline cookie-based tracking on your site.
Conversion modelling works by analysing patterns across large volumes of cookieless pings. Microsoft looks at observable signals such as session timing, device category, and the type of page visited. It identifies patterns shared between non-consenting sessions and consenting sessions that ended in a verified conversion. These patterns come from users who did grant consent and whose full data was captured. The statistical relationships found are then applied to the non-consenting segment to produce a conversion estimate.
The result is an estimated conversion figure that reflects the likely number of sales, registrations, or other tracked goals completed by users who declined cookies. This estimate is added to your Bing Ads reports to give a more complete view of campaign performance.
The modelling process does not operate on guesswork. Microsoft’s system identifies relationships between observable signals from denied-consent pings and known conversion patterns from consenting users. It calculates a probability that a given non-consenting session resulted in a conversion, based on how closely the session resembles verified converting patterns in the consenting data set.
With consent mode active and modelling in place, your reported conversions include a statistically derived estimate from denied-consent sessions alongside directly tracked events. Advertisers seeking to understand this fully should explore how consent mode directly influences UET conversion data and how modelled figures compare to directly tracked ones.
Modelled conversions appear in your Microsoft Advertising dashboard alongside directly tracked conversions. This gives you a fuller picture when assessing which campaigns, ad groups, or keywords are driving actual business results. Without modelling, a campaign converting heavily among non-consenting users may appear underperforming, leading to incorrect budget cuts.
Consent-based marketing built on accurate data allows you to allocate spend with greater confidence. Conversion modelling is what makes that accuracy possible when full cookie tracking is unavailable.
Remarketing in Microsoft Advertising depends on UET data, and consent mode v2 determines whether each user is added to your audience lists based on their consent choice.
When a user grants consent, the UET tag fires fully and adds the visitor to any applicable remarketing lists based on the pages they visited, the actions they took, or the products they viewed. The user is identified via a cookie and assigned to the relevant audience segment within Microsoft Advertising. This is standard behaviour and continues to work exactly as it has under full tracking mode.
When a user declines consent, the tag fires a cookieless ping but does not add the user to any remarketing list. No audience segment is updated for that session, and no profile is created. Microsoft’s system enforces this automatically by reading the ad_storage parameter, without requiring additional rules or manual filters from your team.
Adding non-consenting users to remarketing lists would constitute a breach of GDPR and similar regulations across the EEA, the UK, and beyond. Consent mode v2 prevents this automatically by tying remarketing list updates directly to the ad_storage consent value. If the value is denied, the list membership action does not execute. This is particularly relevant for advertisers targeting professional audiences in regulated markets and is a core reason why consent mode matters for better B2B attribution in European markets where regulatory scrutiny on data handling is considerably higher.
Even with some users excluded from list membership due to denied consent, your remarketing campaigns continue to function effectively. First-party data collected through consented sessions becomes the foundation of your remarketing, rather than a mixed pool of consented and non-consented identifiers. Users captured are verified, legally sound, and more reliable as inputs for bid strategies and audience optimisation.
Here is what this means for your remarketing setup in practice:
Microsoft consent mode v2 improves Bing Ads tracking by responding to each user’s consent choice in real time. The UET tag adapts via ad_storage signals, cookieless pings preserve signal without storing identities, conversion modelling fills attribution gaps, and remarketing lists remain compliant. Advertisers who implement this correctly build campaign data that is both more complete and legally defensible.
Seers connects directly to your UET tag and consent banner to ensure Microsoft consent mode v2 is configured correctly from day one. No manual code edits. No compliance gaps. Your Bing Ads campaigns keep measuring performance while respecting every user's choice across the EEA, UK, and beyond.
START FREE TODAYThe UET tag sends a cookieless ping that carries no personal identifiers. It includes the asc parameter set to D to signal denied consent. Microsoft receives a record that a visit occurred but cannot link it to a specific user, device, or ad click. This allows a measurement signal to remain partially active without storing any data that could identify the individual visitor on your site.
Microsoft’s approach uses aggregated anonymised data from denied-consent pings to estimate missing conversions, which is conceptually similar to Google’s method. However, the two systems operate independently and use different data sets. Advertisers running campaigns on both platforms need separate consent mode configurations for each. Microsoft’s modelling is built specifically around UET signal patterns and Microsoft Advertising conversion data, not Google Analytics signals.
Your existing UET tag does not need to be replaced. What needs to change is the consent signal passed to it. Your consent management platform must be configured to send the ad_storage value to the UET tag based on each user’s banner interaction. Once that signal path is active, the tag adjusts its behaviour automatically. No additional changes to the tag code itself are typically required for this to work correctly.
Directly tracked conversions may appear lower initially, particularly in markets where many users decline cookies. Conversion modelling then estimates the conversions missed due to denied consent and adds them to your reporting. The total picture should be more complete than before, not less. Advertisers tracking without consent mode were often missing data entirely or receiving inaccurate signals due to the absence of proper denied-consent handling in their measurement setup.
Consent mode v2 applies to any campaign that uses UET for conversion tracking or remarketing, which covers the vast majority of Microsoft Advertising campaigns. It became mandatory for advertisers using UET in the EEA, UK, and Switzerland as of May 2025. Campaigns targeting audiences outside these regions may not face the same regulatory requirements but can still benefit from the improved measurement accuracy that consent mode provides across all markets.
Consent mode v2 can be implemented manually using custom JavaScript that passes the ad_storage value to the UET tag. However, this approach requires developer resources, ongoing maintenance, and careful testing across different consent scenarios. A dedicated consent management platform handles this automatically, keeps your implementation current with regulatory changes, and reduces the risk of misconfiguration that could result in incorrect consent signals being sent to your UET tag.
Users who decline consent are not added to remarketing lists under consent mode v2. If a significant proportion of your EEA audience declines, your lists will grow more slowly in those markets. However, the users who are added have actively consented, making the list legally sound and the audience more reliable for targeting. Campaign performance from consented audiences tends to be more consistent than performance from audiences built on mixed or non-consented data.
Rimsha ZafarRimsha is a Senior Content Writer at Seers AI with over 5 years of experience in advanced technologies and AI-driven tools. Her expertise as a research analyst shapes clear, thoughtful insights into responsible data use, trust, and future-facing technologies.
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