Microsoft Advertising API Adds PMax Device Exclusions and Search Reporting

Microsoft Advertising expanded its API capabilities for managing Performance Max and introduced more detailed reporting that connects search queries with ad headlines and landing pages.

The updates were included in the August Microsoft Advertising API release and received additional coverage in industry publications on September 25, 2026. Key changes include device exclusions at the PMax campaign level, the new Search Term Landing Page Report, and programmatic access to LinkedIn segments.

For advertisers, this is another step toward greater transparency in automated advertising. Performance Max still makes a substantial share of advertising decisions automatically, but agencies and developers now have additional tools for campaign control and performance diagnostics.

These changes are especially important for companies using Microsoft Advertising API to build their own analytics systems, automated audits, and tools for managing large numbers of advertising accounts.

What Is Microsoft Advertising Performance Max?

Performance Max (PMax) is an automated campaign type in Microsoft Advertising that combines promotion across different advertising placements within the Microsoft ecosystem.

Unlike a traditional Search campaign, where the advertiser manages keywords, ads, and search advertising settings, Performance Max uses machine learning to select audiences, advertising assets, and delivery conditions.

The advertiser defines a business objective, budget, and bidding strategy, uploads advertising assets, and connects a product catalog when necessary.

Microsoft Advertising then uses these inputs to automatically assemble and deliver ads.

An important component of PMax is Asset Groups, which contain headlines, descriptions, images, videos, and other advertising assets. The algorithm combines these materials and selects appropriate variations for different advertising situations.

Performance Max can be used for e-commerce, lead generation, and other conversion-focused objectives.

The advantage of automation is the ability to manage advertising across multiple placements without creating separate campaigns for each inventory type.

However, this approach also creates limitations. Advertisers cannot always determine exactly why the algorithm selected a particular user, device, combination of assets, or landing page.

This is why Microsoft has been gradually expanding PMax reporting and control settings.

What Is Microsoft Advertising API?

Microsoft Advertising API is a programming interface that allows external applications to interact with the advertising platform.

Through the API, agencies and developers can retrieve performance statistics, create campaigns, modify settings, manage advertising assets, and perform bulk operations.

For example, an agency manages 200 advertising accounts. Instead of manually analyzing each account, it can use its own system to retrieve Microsoft Advertising data daily, identify anomalies, and generate recommendations.

The API is particularly important for Performance Max.

The more decisions the algorithm makes, the more important it becomes to obtain detailed performance data and apply necessary business restrictions.

This does not necessarily involve changing the automated bidding model itself. In many cases, obtaining additional information or being able to exclude clearly unsuitable delivery conditions is enough.

The August API expansion is aimed at precisely these tasks.

What Changed in Microsoft Advertising API?

Three important changes appeared in the August Microsoft Advertising API release notes.

First, support for device exclusions at the Performance Max campaign level.

Second, the new Search Term Landing Page Report, which allows advertisers to analyze the relationship between a search query, the delivered ad headline, and the final URL.

Third, new interfaces for working with LinkedIn segments, including CustomLinkedInCriterion and GetLinkedInSegments.

These changes address different needs. Device exclusions expand control over ad delivery. The new report improves search traffic diagnostics. LinkedIn interfaces expand programmatic capabilities for working with professional audiences in supported Microsoft Advertising scenarios.

However, it is important to distinguish between support for a feature in the API, in a particular SDK, and in the advertising platform's user interface. The presence of a new method or field does not mean every third-party tool has already implemented support for it.

1. Device Exclusions for Performance Max

One of the most practical updates is support for device exclusions at the PMax campaign level.

Microsoft Advertising allows advertisers to exclude three device categories:

• Computers: Desktop and laptop computers.
• Smartphones: Mobile phones.
• Tablets: Tablet devices.

This is not a new bidding strategy or an option to manually set a separate CPC for each device category.

These are exclusions: advertisers specify which devices their campaigns should not serve ads on.

How Device Management Worked Before

Performance Max was originally designed as an automated system that independently distributes impressions across available advertising inventory.

Advertisers could analyze performance by device, but the ability to apply strict restrictions in PMax was less flexible than in traditional campaign types.

For companies using the API and proprietary advertising management systems, this created an additional problem: some business rules could not be implemented consistently across Search and Performance Max.

For example, an advertiser might use an automated audit that identifies campaigns with inefficient mobile traffic. However, applying a device exclusion rule to PMax was more difficult because of limitations in the available interfaces.

What Changed

Microsoft Advertising API documentation now specifies support for DeviceCriterion in exclusion mode at the Performance Max campaign level.

Bulk Service also added support for BulkCampaignNegativeDeviceCriterion in the .NET SDK.

This allows developers to incorporate device exclusion management into their own automation workflows.

For example, a system can inspect advertising campaigns, identify unwanted device categories, and create exclusions through a supported API mechanism.

However, actual availability depends on the specific API client, SDK version, and supported operations.

Practical Example: B2B Lead Generation

Suppose a company promotes complex enterprise software.

Its website is mobile-friendly, but the inquiry process includes a detailed form, document uploads, and the selection of corporate parameters.

Historical performance data may show that mobile traffic generates substantially more initial inquiries, while the share of qualified leads and closed deals is significantly lower than on computers.

In this situation, excluding smartphones can potentially restrict impressions on devices that do not align with the company's current commercial model.

However, the decision should not be based solely on CPL or website Conversion Rate. Advertisers must consider lead quality, subsequent CRM statuses, and the impact of the restriction on overall sales volume.

Practical Example: Online Retail

Suppose an online retailer generates most of its purchases from smartphones, while tablets produce relatively few sales at a high customer acquisition cost.

Excluding tablets may be justified if the results are supported by sufficient data.

However, Performance Max uses automated optimization. Removing an entire device category restricts available inventory and may change the distribution of advertising impressions.

Therefore, exclusions should be treated as a way to implement justified business restrictions, not as a universal method for improving ROAS.

What the New Controls Do Not Allow

Support for DeviceCriterion does not mean advertisers gain complete control over all PMax decisions.

In particular, it does not provide manual bidding adjustments for computers, smartphones, and tablets.

Microsoft Advertising API describes DeviceCriterion for Performance Max as an exclusion criterion. Device controls should not be interpreted as the return of traditional bid adjustments to automated campaigns.

2. Search Term Landing Page Report: More Detailed Search Traffic Reporting

The second major update is the introduction of the Search Term Landing Page Report.

This report combines information about the user's search query, the delivered ad headline, and the final landing page.

Previously, advertisers could analyze search queries, ads, and landing pages through separate reports.

However, connecting these data points within the same advertising situation was more difficult.

The new report helps advertisers understand how closely the advertising message and selected page match the user's actual intent.

How the Search Term Landing Page Report Works

Microsoft Advertising Reporting API added the SearchTermLandingPageReportRequest object.

It allows advertisers to request data connecting several characteristics of an advertising interaction.

Parameter	What It Shows
Search Term	The user's search query
Delivered Headline	The headline displayed in the ad
Final URL	The final landing page
Performance Metrics	Supported performance indicators

Microsoft's documentation specifies that generating the report requires the Final URL field and at least one performance metric.

After retrieving the data, advertisers can analyze it in their own systems, combine it with CRM information, or use it to identify problems in campaign structure.

Practical Example: Mismatch Between Search Query and Landing Page

Suppose an online retailer sells office furniture.

A user enters the search query "ergonomic office chair with lumbar support."

The algorithm displays an ad with the headline "Office Furniture for Every Workspace" but directs the user to a general furniture catalog page.

Technically, the advertising message is related to the user's interest, but the landing page does not immediately offer the specific product category they need.

In the new report, a specialist can identify this sequence:

Search query → delivered headline → landing page.

If similar situations are repeatedly associated with a low Conversion Rate, this becomes a reason for further investigation.

The solution may involve changing advertising assets, improving landing pages, or adjusting supported traffic-routing settings.

However, the report itself does not change ad delivery. It provides diagnostic data.

Why This Matters for Automated Advertising

In traditional Search campaigns, advertisers have more control over the relationship between keywords, ads, and landing pages.

In automated campaign types, the algorithm makes some of these decisions.

As a result, strong overall campaign metrics may conceal individual combinations of search queries, advertising messages, and pages that perform poorly.

The new report allows advertisers to conduct audits not only at the campaign or URL level, but also with search intent in mind.

For agencies, this is particularly valuable when analyzing traffic quality and preparing recommendations for clients.

However, the introduction of the Search Term Landing Page Report should not be confused with a new bidding optimization mechanism.

Microsoft's documentation describes it as a tool for analyzing search queries, ad headlines, and landing pages. Its availability does not automatically improve CTR, CPA, or ROAS.

3. LinkedIn Segment Support Through Microsoft Advertising API

The third change involves new interfaces for working with LinkedIn segments.

The August Microsoft Advertising API release introduced CustomLinkedInCriterion and GetLinkedInSegments.

LinkedIn is an important source of professional audience characteristics within the Microsoft advertising ecosystem.

This information is particularly valuable for B2B advertisers because it allows them to consider prospective customers' professional context.

For example, an advertiser may be interested in audiences associated with particular companies, industries, or professional categories, provided the selected campaign type supports the relevant parameters.

What Changes for Developers

The new interfaces allow developers to work programmatically with supported LinkedIn segments within Microsoft Advertising.

For agencies, this can potentially simplify the standardization of B2B advertising settings.

For example, a company manages several dozen advertising accounts for corporate clients.

Its internal application can use available API interfaces to retrieve information about supported segments and apply corresponding criteria in permitted advertising scenarios.

However, compatibility limitations must be taken into account.

The addition of LinkedIn interfaces to Microsoft Advertising API does not mean that all professional segments can now be used directly as strict targeting criteria in Performance Max.

For any specific strategy, advertisers must verify supported campaign types, targeting criteria, and available operations.

Otherwise, there is a risk of attributing capabilities to the update that it does not actually provide.

How the New API Features Relate to Earlier PMax Updates

The August and September API expansion did not occur in isolation.

Throughout 2026, Microsoft has been steadily increasing Performance Max transparency.

In April and May, the company expanded reporting for landing pages and search queries.

Advertisers gained the ability to analyze performance for individual Final URLs, including spending, impressions, clicks, conversions, and profitability metrics.

In August, Microsoft also announced expanded search reporting, Uplift Experiments, and demographic controls.

Uplift Experiments allow advertisers to evaluate the incremental results of adding Performance Max to existing advertising campaigns.

Demographic exclusions help restrict impressions by age and gender categories.

The new API controls continue this trend but address different tasks.

Essentially, Microsoft is developing three areas:

1. Transparency. Advertisers receive more detailed data about which queries, assets, and landing pages are involved in ad delivery.
2. Control. Additional restrictions make it possible to account for business conditions that automation cannot always identify on its own.
3. Management automation. Agencies can use new data and settings in their own software, reports, and audit processes.

This does not represent a move away from Performance Max as an automated system.

On the contrary, Microsoft retains automated management of core advertising decisions while gradually giving advertisers more tools to inspect and restrict algorithmic behavior.

What the Update Means for Advertising Agencies

For agencies managing large numbers of advertising accounts, the new capabilities are primarily important from an operational perspective.

More Detailed Automated Audits

A proprietary analytics system can retrieve Search Term Landing Page Report data and identify problematic combinations of queries, ad headlines, and landing pages.

For example, it can detect situations where advertising traffic is directed to overly general pages or pages that do not match the user's apparent intent.

However, such rules require caution. An algorithmic audit may identify a suspicious combination, but it cannot always establish commercial inefficiency without analyzing actual conversions.

Centralized Device Restrictions

For campaigns where certain devices are genuinely unsuitable, the API makes it possible to incorporate relevant exclusions into standard management workflows.

For example, an agency can verify that device restrictions align with a client's website requirements or agreed advertising strategy.

This is particularly relevant to companies with internal policies governing the use of advertising inventory.

Improved Client Reporting

The new data allows agencies to explain Performance Max results more specifically.

Instead of simply stating that a campaign achieved a certain CPA, an agency can also analyze search queries, advertising messages, and landing pages.

For clients, this provides a more transparent picture of how automated advertising attracts users.

However, additional reporting detail does not eliminate all attribution limitations. Microsoft Advertising reports still reflect results according to the platform's own measurement rules.

How Developers Can Prepare to Use the New Features

The first step is to determine which versions of Microsoft Advertising API and its SDKs are being used in the existing integration.

Official release notes describe new Campaign Management API interfaces, a Reporting API report, and Bulk Service changes.

Developers should therefore verify support for the relevant objects and operations in their specific client.

Checking the Search Term Landing Page Report

To integrate the report, developers should review SearchTermLandingPageReportRequest in the Reporting API documentation.

They should then construct a request using the required fields and supported metrics.

After retrieving the data, they should verify:

• The availability of search queries and delivered headlines.
• The accuracy of Final URLs.
• The availability of required performance metrics.
• The ability to match data with campaigns and other objects.
• The reliability of recurring report exports.

It is important to remember that the introduction of a new report does not guarantee complete data for every advertising interaction.

Checking Device Exclusions

For device management, developers should review DeviceCriterion and the supported operations for campaign criteria.

In Microsoft Advertising API, device exclusions are configured as negative campaign criteria.

Before applying them in bulk, developers should verify that the operation is supported for the relevant campaign type and ensure that the exclusion does not conflict with existing settings.

Error handling should also be tested.

If an external tool attempts to apply an unsupported criterion, the system should correctly record the error rather than treating the change as successfully completed.

Checking LinkedIn Segments

For the new LinkedIn interfaces, developers should verify the availability of GetLinkedInSegments and the compatibility of CustomLinkedInCriterion with their intended audience management scenarios.

Particular attention should be paid to the difference between segments available for configuration and those that can be used only in certain campaign types.

Developers should not automatically apply conventional Search campaign logic to Performance Max without checking the documentation.

Do the New API Controls Affect CPA and ROAS?

The update does not directly change the automated bidding algorithms.

Search Term Landing Page Report is an analytics tool.

DeviceCriterion allows advertisers to restrict ad delivery on specific devices.

The LinkedIn interfaces expand programmatic capabilities for working with supported audiences.

None of these tools, by itself, guarantees more conversions or lower conversion costs.

Any positive impact may occur after advertisers use the new data to make appropriate decisions.

For example, identifying an irrelevant landing page may lead to an improved user experience and a higher Conversion Rate.

However, a similar intervention based on insufficient data can make results worse.

Excluding devices may eliminate clearly unsuitable traffic, but it can also reduce the algorithm's opportunities to find new customers.

As of October 2026, there is insufficient independent research to determine the average impact of these specific API updates on CPA, ROAS, or sales volume.

They should therefore be evaluated primarily as an expansion of management and diagnostic tools, rather than as an independent method for improving advertising efficiency.

Affect's Takeaway: Automation Is Becoming More Transparent, but Not Less Automated

The new Microsoft Advertising API capabilities continue the development of Performance Max toward greater transparency and control.

Advertisers gain tools to exclude unwanted devices, analyze the connection between search queries, ad headlines, and landing pages in greater detail, and programmatically work with supported LinkedIn segments.

For large agencies and advertising platform developers, this creates opportunities to build more precise audit systems, apply business restrictions centrally, and improve reporting.

At the same time, Performance Max continues to manage a substantial share of advertising decisions automatically.

Microsoft is not giving advertisers complete control over audience selection, placements, or bids. The new interfaces allow them to refine the rules governing algorithmic behavior and better understand results, but they do not replace its automated logic.

Affect recommends using the expanded API capabilities primarily to improve analytics quality and enforce business restrictions.

The main value of the update is not the promise of cheaper conversions, but the ability to make better-informed decisions about automated advertising campaigns.

Sources

1. Microsoft Advertising API: Release Notes, August 2026. Microsoft Learn
2. Microsoft Learn: Performance Max Campaigns. Microsoft Learn
3. Microsoft Learn: Report Types, including Search Term Landing Page Report. Microsoft Learn
4. Search Engine Land, September 25, 2026: Microsoft Ads API Adds Deeper Search Reporting and More PMax Controls. Search Engine Land
5. Microsoft Advertising, May 7, 2026: Providing More Transparency for Your Performance Max Campaigns. Microsoft Advertising
6. Microsoft Advertising, August 2026: AI Max for Search and Other Product News for August 2026. Microsoft Advertising
7. Microsoft Advertising, April 2026: Performance Max Updates and Other Product News for April 2026. Microsoft Advertising