Startups: Companies that are in their initial stages of business and typically developing a business model and seeking financing.
Hi @Oleksii Ivanov ,
Referral code: Yes, you can apply with an investor referral code. Microsoft's application guide has you enter the 10-character code on the "Apply for Microsoft for Startups" step.
Existing Entra ID tenant: You can't sign up with an identity from that tenant. Sign-up requires a personal Microsoft account (MSA) with no prior Azure use, and work, school, or Entra ID accounts aren't accepted for sign-up or credit activation (FAQ).
Using the credits in another tenant: The credits are activated as an Azure Sponsorship subscription under that MSA. A Microsoft moderator has said that moving a Sponsorship subscription between tenants isn't supported. I couldn't find official Microsoft for Startups documentation that confirms or contradicts this. Separately, an entitlement transfer to an existing subscription was handled manually by the Startups team on request.
Since activation looks irreversible (you have 90 days to activate, and an MSA that has already redeemed can't redeem again), I'd contact Program Support before redeeming. Use Get Program Support in the Azure portal, or aka.ms/startuphelp-mfs-portal if you don't have an account yet. Ask them directly whether the sponsorship subscription can be associated with your existing tenant.