To Satya Nadella, CEO, Microsoft Corporation

 
Who We Are

We are startup founders participating in the Microsoft for Startups program. Cloud credits from vendor programs are a lifeline for early-stage companies with limited runway. We chose Azure because we trusted Microsoft. That trust has been exploited.

What Happened

Azure AI Foundry displays both Microsoft-native models (such as Azure OpenAI) and third-party Marketplace models (such as Anthropic Claude) in a completely unified interface — with no visual distinction, no warning, and no confirmation step before charges are incurred.

The specific problems with the UI:

• No "Marketplace" label anywhere in the model deployment flow
• No warning that Microsoft for Startups credits do not apply to these models
• No confirmation prompt before third-party billing is activated
• In Azure Cost Management, credit balances do not decrease while Marketplace charges accumulate silently on your credit card — making it impossible to detect the problem until the invoice arrives

The result: founders believe they are operating within their free credit tier while charges pile up on their personal or company credit cards in the background.

Documented Cases

The following cases have been confirmed across multiple countries:

• Japan, Startup Founder A: ¥237,081 (~$1,600 USD) — full case documented here: https://zenn.dev/leach/articles/a8a71f886ec6aa
• Japan, Startup Founder B: Over ¥2,000,000 (~$13,000 USD) — incurred within a single month
• Germany / EU, Startup Founder: €999.60

These are only the cases we are currently aware of. Given the scale of the Microsoft for Startups program globally, the actual number of affected founders is likely far greater.

What Microsoft and Anthropic Said

When affected founders contacted Microsoft support, the response was: "Marketplace products are not covered by startup credits. Please contact the publisher (Anthropic) directly for a refund."

When founders contacted Anthropic, the response was: "We do not have visibility into usage through Microsoft Foundry and are unable to process a refund. This is our final decision. We may not be able to respond to further messages regarding this matter."

The complete picture:

 

 

 

 

 

Both companies have now confirmed in writing that neither will take responsibility. The structure is designed so that no one is accountable — by design.

 

"It's in the Documentation" — Except Microsoft's Own Staff Said Otherwise

Some have argued that the billing exclusion is clearly documented and that affected
founders simply failed to read the terms.

However, on December 2, 2025, Sridhar M — a Microsoft External Staff member and
Moderator with 3,895 reputation points on Microsoft's official Q&A platform —
answered a question about Claude Opus 4.5 pricing on Azure AI Foundry with the
following statement:

"Startup credits (Azure Sponsorship) apply to these charges until the credit
balance is exhausted."

This answer was given on Microsoft's own support platform, by a Microsoft-badged
staff member, to a founder asking the exact question every startup founder would ask
before scaling usage.

 

 

 

 

 

Archived proof:
https://web.archive.org/web/20260112075754/https://learn.microsoft.com/en-us/answers/questions/5642942/do-you-know-the-price-of-claude-opus-4-5

When Microsoft's own staff cannot correctly identify which models are covered by
startup credits, the argument that founders should have known better is untenable.
This is not a documentation problem. This is a systemic failure — from the UI to the
support channel.

 

Why This Matters

This is not a billing error. Microsoft designed and operates the Azure AI Foundry platform. Microsoft chose to surface third-party Marketplace models in the same unified interface as native Azure services, with no visual distinction. Microsoft for Startups participants — who joined the program specifically to build on Azure — cannot reasonably be expected to identify a billing trap buried in documentation when the UI itself gives no indication that different billing rules apply.

This is a consumer protection issue. In Japan, a formal report has been filed with the Japan Fair Trade Commission (JFTC). EU-based founders are considering filings with relevant consumer protection authorities in their jurisdictions. Legal counsel in Japan has assessed that the case for court action is strong.

Microsoft's own Q&A thread documenting this issue — posted by an affected EU founder in January 2026 — was locked by Microsoft shortly after additional victims added their accounts. The thread remains locked.

What We Are Asking For

1. Immediate UI fix: Add a clear warning and confirmation step when deploying Marketplace models in Azure AI Foundry, explicitly stating that startup credits do not apply and that charges will be billed directly to the user's payment method.
2. Visual distinction: Clearly differentiate Microsoft-native models from third-party Marketplace models throughout the deployment interface.
3. Full refunds: Reimburse all Microsoft for Startups participants who incurred unexpected charges due to this UI design.
4. Public commitment: Publish a formal statement acknowledging the issue and the steps being taken to prevent recurrence.

If You Have Been Affected

If you have experienced the same issue as a Microsoft for Startups participant, please sign this petition and share your case. Coordinated reports from multiple founders across multiple jurisdictions are the most effective path to forcing a resolution.

 

Resources and Evidence

Full technical documentation (English):
https://zenn.dev/leach/articles/a8a71f886ec6aa

日本語版（Japanese version）:
https://zenn.dev/leach/articles/f80b10781fc768

X (Twitter) thread documenting the case and ongoing developments:
https://x.com/takuya_tominaga/status/2022520650355872187

Microsoft Q&A thread by affected EU founder (locked by Microsoft):
https://learn.microsoft.com/en-us/answers/questions/5728641/azure-ai-foundry-presents-third-party-ai-models-as

Microsoft staff's incorrect billing guidance (archived):
https://web.archive.org/web/20260112075754/https://learn.microsoft.com/en-us/answers/questions/5642942/do-you-know-the-price-of-claude-opus-4-5

Reddit discussion (r/AZURE):
https://www.reddit.com/r/AZURE/comments/1rqw9pn/microsoft_and_anthropic_both_refused_to_refund/