Salesforce and Slack sue Microsoft in UK over Teams bundling as global antitrust pressure intensifies

Microsoft is facing fresh legal pressure in Europe after Salesforce and its workplace messaging platform Slack filed a lawsuit in London’s High Court, accusing the company of using its dominance in business software to suppress competition. The case centers on Microsoft’s long criticized practice of bundling Teams with its Office productivity suite, a strategy rivals say unfairly limits customer choice and locks businesses into Microsoft’s ecosystem.

The legal challenge marks another chapter in a widening global dispute over how large technology companies package software products, price enterprise tools, and use scale to strengthen their position in adjacent markets.

According to reports, Slack alleges that Microsoft tied Teams to Office products in a way that effectively pushed the communications platform onto enterprise customers already dependent on Word, Excel, Outlook, and other widely used Microsoft tools.

Slack argues that many businesses purchased Microsoft productivity subscriptions and received Teams as part of the package, reducing the incentive to pay separately for competing collaboration tools. The company says this made it harder for rivals to compete on merit, innovation, or pricing.

A spokesperson for Slack said Microsoft’s practices harmed competition by using tying and bundling of Teams to reduce customer choice.

This complaint reflects concerns Slack has raised for several years. In 2020, the company filed a similar case with European regulators, arguing that Microsoft leveraged its Office dominance to expand Teams rapidly across the workplace communications market.

Microsoft Teams became one of the fastest growing workplace software products during the global shift to remote and hybrid work. As companies rushed to adopt video meetings, chat platforms, and digital collaboration tools, Teams benefited from being deeply integrated into Microsoft’s existing enterprise ecosystem.

For many organizations, adopting Teams required little additional purchasing or deployment effort because Microsoft already supplied core software infrastructure. That convenience helped accelerate growth, but competitors argue the same advantage also distorted the market.

Rivals claim that when a communication tool is bundled into a broader subscription package, standalone competitors must convince customers to pay extra for alternatives, creating a structural disadvantage.

This has made Teams a recurring focus for regulators, rivals, and antitrust authorities across multiple jurisdictions.

The new lawsuit in the United Kingdom suggests Microsoft’s earlier concessions in Europe did not fully resolve competitor concerns.

Last year, Microsoft adjusted pricing for some Office products in Europe, allowing customers to choose versions without Teams at a lower cost. The move was widely seen as an attempt to address regulatory scrutiny and avoid significant penalties.

However, the London High Court case indicates that some rivals believe those changes were either too limited or too late to restore fair competition.

The UK case could become significant because Britain remains one of the most important markets for enterprise technology services, cloud infrastructure, and workplace productivity software.

The lawsuit comes after Google previously criticized Microsoft’s enterprise tactics in Europe. Google described certain Microsoft practices as problematic and accused the company of using dominant software products to steer customers toward its Azure cloud platform.

Google’s earlier complaint focused on Windows Server licensing and interoperability issues. It argued that businesses using Microsoft software could face disadvantages when trying to run workloads on competing cloud providers.

Although Google later withdrew that specific complaint to allow regulators to pursue a broader review, the dispute highlighted growing tensions between major cloud and software vendors over licensing power, compatibility, and platform control.

The fact that both Slack and Google have publicly challenged Microsoft on competition grounds adds weight to the broader industry concern that enterprise markets may be becoming harder for rivals to contest.

Microsoft is also dealing with competition scrutiny in the United States. Reports earlier this year said the Federal Trade Commission was accelerating an investigation into whether Microsoft has used its market power unfairly in enterprise computing.

That reported probe is said to examine whether Microsoft makes it harder for customers to run Windows or Office effectively on rival cloud services such as those offered by Amazon or Google.

Regulators were also reportedly reviewing whether Microsoft’s integration of Copilot artificial intelligence tools and security software into Windows could disadvantage competitors.

If multiple jurisdictions pursue related concerns at the same time, Microsoft could face a more complex regulatory environment than at any point in recent years.

Microsoft has maintained that its products are designed to deliver integrated value for customers and that differences in compatibility often reflect technical realities rather than anti competitive intent.

The company has argued that some services may not work identically on rival cloud systems because the underlying architecture differs. Microsoft also points to intense competition across cloud computing, productivity software, cybersecurity, and AI tools.

Supporters of Microsoft’s approach say customers often prefer unified platforms that reduce cost, simplify management, and improve security.

Critics counter that integration becomes problematic when a dominant company uses one essential product to advantage another.

For enterprise customers, the outcome of these disputes could shape software pricing, vendor choice, and flexibility for years.

If regulators or courts conclude bundling reduced competition, customers may gain access to more modular pricing models and easier switching between collaboration platforms.

That could benefit businesses seeking best of breed solutions rather than all in one software suites.

On the other hand, some companies value bundled offerings because they can lower procurement complexity and streamline IT operations. Any forced separation of products may create new costs for organizations that prefer a single vendor environment.

The central policy question is whether convenience for customers outweighs the competitive risks of platform dominance.

The Microsoft case reflects a broader shift underway in technology markets. Traditional battles over operating systems and browsers have evolved into disputes over cloud platforms, workplace ecosystems, cybersecurity layers, and artificial intelligence assistants.

Today’s enterprise software giants are competing not just on product quality, but on ecosystem control. Whoever owns the operating system, productivity suite, cloud platform, and AI layer can shape how customers buy and use technology.

That makes antitrust scrutiny increasingly likely as governments try to ensure markets remain open to challengers.

The London lawsuit may take time to move through the courts, but its significance is immediate. It signals that rivals are no longer relying only on regulators and are prepared to pursue direct legal remedies.

For Microsoft, the challenge is balancing product integration with competition concerns at a moment when it is also expanding aggressively in cloud computing and artificial intelligence.

For Salesforce, Slack, Google, and other competitors, the case is an opportunity to argue that enterprise customers deserve genuine choice rather than default adoption driven by market power.

As the legal and regulatory battles continue, one thing is clear: the fight over Teams bundling is no longer just about chat software. It is about who controls the future of digital work.