A Norwegian startup says it ran up a $17,600 bill using Claude in Microsoft Foundry after assuming its Azure credits would cover the cost.
We reported a similar case in March, involving third-party model charges that weren't covered by Azure sponsorship credits.
This time, the customer says Microsoft and Anthropic each directed it to the other to resolve the charges.
Vegalabs AS says it received $25,060 in Azure credits through Microsoft for Startups and deployed Claude in August, expecting its analysis workloads to use that balance.
However, Microsoft's sponsorship rules exclude Anthropic models purchased through Azure Marketplace. Vegalabs says Microsoft attempted to collect $16,500 from its card, with the invoiced total subsequently reaching $17,600 before tax.
Vegalabs says it monitored the sponsorship portal, which continued to show available credits while separate Marketplace charges accumulated. Microsoft's Claude deployment guide says credit-only sponsored subscriptions aren't supported, but accounts with a card on file will have that card charged instead.
The company says it deleted the deployment within an hour of discovering the charges. Its card issuer declined the attempted payment over suspected fraud, and $21,168 in unused sponsorship credits expired on September 8.
Vegalabs acknowledges it did not read the credit exclusions or configure a budget alert. It disputes neither the usage nor the documented rule, but says the deployment interface failed to make the separate billing clear. Its request for a waiver then bounced between Microsoft and Anthropic support.
has seen communications from Microsoft directing the user to Anthropic. "Marketplace transactions are processed through a separate billing pipeline associated with the third-party publisher. As a result, Azure Support does not have the ability to directly waive, refund, or adjust these Marketplace charges on the customer's behalf."
"If Anthropic approves the request, they can initiate the appropriate refund authorization through Microsoft."
Anthropic support, however, said Microsoft did not require its authorization to process a refund and directed Vegalabs back to Microsoft.
Vegalabs says four of the seven support replies it received were AI-generated, including both responses from Anthropic. It says those responses incorrectly described its account as an "Azure Student Sponsorship."
We asked Microsoft on October 6 if it had any comment on the situation, but beyond an acknowledgment and a request to let us know what Anthropic had to say, the company had nothing further to share. We also asked Anthropic for its take on the situation, but the company did not respond.
Microsoft's rules distinguish between credit-covered services and separately billed models offered through the same platform. Vegalabs' experience suggests that distinction needs to be clearer where customers deploy them.
For now, the company has a bill and two support teams directing it elsewhere. ®