Hey @RealGR! Klaviyo leverages Twilio and Infobip for our SMS services. We generally don’t publish that in official documentation so if you’re asking for a specific reason I’ll see what I can do to point you in the right direction. 

Thank you for that information. Our business was acquired and the acquiring company asked that question. Can you clarify if both are being used for our account or only Twilio? 

Unfortunately, I can’t confirm either way because I don’t have access to your Klaviyo account. For further information I suggest reaching out to our Support team and see what they can tell you!

I did. They says Twilio.