Microsoft Teams bundling with Office 365 is now the subject of formal litigation in London, as Slack’s parent company Salesforce escalates a three-year-old complaint into active court proceedings. The lawsuit alleges that Microsoft uses anticompetitive tying to lock customers into Teams, denying rivals a level playing field. Microsoft’s response: Slack simply failed to innovate when it mattered most.
Key Takeaways
- Salesforce filed a formal antitrust lawsuit against Microsoft in London court over Teams bundling with Office 365.
- Microsoft spokesperson claimed Slack’s slower growth compared to Zoom and Teams resulted from inferior capabilities during COVID-19, not bundling practices.
- Microsoft’s bundling extends beyond Teams, including OneDrive, Defender, and Azure self-preferencing, according to broader antitrust complaints.
- European customers face estimated €1 billion annual surcharges for SQL Server outside Azure and 28% higher Office 365 license costs outside the cloud platform.
- EU regulators remain actively investigating broader Microsoft licensing and pricing practices through the DG Competition authority.
The London Court Case: Slack and Salesforce’s Bundling Challenge
Slack and Salesforce launched formal litigation against Microsoft in a London court, directly targeting what they describe as illegal tying of Teams with Office 365. The complaint, originally raised over three years ago, alleges that Microsoft weaponized its dominant Office position to crush a competitor in workplace chat. This is not a theoretical grievance—it is a live legal battle with specific allegations of market abuse. The lawsuit represents a significant escalation from earlier complaints, moving from regulatory channels into the courtroom.
The core argument is straightforward: by bundling Teams with Office 365, Microsoft forced customers to adopt Teams whether they wanted it or not. Slack argues this created an impossible competitive environment. Why would a company pay separately for Slack when Teams came free with their Office subscription? The bundling strategy, according to the complaint, denied Slack a fair chance to compete on product merit alone.
Microsoft’s Defense: Blame Slack’s Product, Not Our Bundling
Microsoft’s response rejects the bundling narrative entirely. A Microsoft spokesperson stated that Salesforce’s complaint is baseless, attributing Slack’s lackluster growth compared to Zoom and Teams to inferior capabilities when COVID-19 hit in 2020. This framing shifts accountability from Microsoft’s distribution power to Slack’s product execution. The argument suggests that Teams won not through forced bundling but through better features when remote work exploded.
Yet this defense glosses over a critical detail: Microsoft could claim product superiority while simultaneously leveraging bundling. The two are not mutually exclusive. A product can be genuinely good and still benefit from anticompetitive distribution. The presence of bundling does not require Slack to have been technically superior—it only requires that bundling reduced the playing field’s fairness. Microsoft’s argument essentially claims that bundling had zero effect on adoption, which strains credibility in a market where distribution and pricing drive adoption as much as features do.
Beyond Teams: Microsoft’s Broader Bundling Strategy
The Teams bundling complaint is part of a larger pattern of Microsoft’s tying practices. According to broader antitrust investigations, Microsoft bundles OneDrive and Defender with Office, self-preferences Azure over competing cloud infrastructures, and uses aggressive pricing to discourage customers from using non-Microsoft services. These practices extend across the entire Microsoft ecosystem, suggesting a systematic strategy rather than isolated incidents.
The pricing impact on European customers illustrates the scale. SQL Server customers face estimated €1 billion in annual surcharges when deployed outside Azure, while Office 365 customers pay approximately 28% more in license costs if they choose non-Microsoft cloud infrastructure. These are not small margins—they represent deliberate pricing structures designed to make alternatives economically irrational. The European Union’s DG Competition authority remains actively investigating these broader licensing and pricing complaints, suggesting regulators view the pattern as serious enough to warrant formal scrutiny.
Why the Timing Matters: A Regulatory Turning Point
The London lawsuit arrives at a critical moment for Microsoft’s antitrust exposure. Regulators globally are scrutinizing bundling practices in cloud and productivity software with renewed intensity. The EU has already launched multiple investigations into Microsoft’s licensing practices. A successful lawsuit in London could embolden regulators elsewhere and expose Microsoft to damages claims. Conversely, a Microsoft victory could signal that bundling, even aggressive bundling, is legally defensible if the bundled product is genuinely competitive.
For Slack and Salesforce, the lawsuit represents a last-resort attempt to level a playing field they argue was never fair. Slack’s market position has stabilized but never recovered to the dominance it might have achieved in a world without Teams bundling. This lawsuit is as much about the principle of competitive fairness as it is about market share.
Is Microsoft’s bundling strategy illegal under UK and EU law?
UK and EU antitrust law prohibit tying when a dominant firm leverages power in one market to foreclose competition in another. Microsoft’s dominance in productivity software is undisputed. Whether bundling Teams with Office constitutes illegal tying depends on whether it materially foreclosed Slack’s ability to compete. The London court will weigh whether Teams’ superiority alone explains its adoption or whether bundling played a decisive role.
What happens if Salesforce wins the lawsuit?
A Salesforce victory could force Microsoft to unbundle Teams from Office 365, allow customers to purchase Office without Teams, or provide pricing discounts for customers who decline Teams. Beyond the immediate remedy, a win would validate the broader EU investigation findings and likely trigger additional regulatory action globally. It would also expose Microsoft to damages claims for lost Slack revenue during the bundling period.
Could this lawsuit affect Microsoft’s other bundling practices?
The lawsuit specifically targets Teams and Office, but a judgment against Microsoft could set precedent for scrutinizing OneDrive, Defender, and Azure bundling practices. Regulators are already investigating these arrangements separately. A successful Teams case would strengthen their legal arguments and increase the likelihood of forced unbundling across multiple Microsoft products.
Microsoft’s defense rests on product quality, but the London court will ultimately decide whether bundling power and product merit can coexist legally. If the court agrees with Salesforce, Microsoft’s entire ecosystem strategy—built on integrated, bundled services—faces serious disruption. If Microsoft prevails, the company signals that dominant firms can use bundling freely as long as the bundled product is competitive. The stakes extend far beyond Slack and Teams into the fundamental question of how dominant tech platforms can package and distribute their services.
This article was written with AI assistance and editorially reviewed.
Source: Windows Central
