### Answer
I understand your concern about unexpected charges. Vapi's billing can vary based on several factors such as the providers used during calls, whether provider keys were supplied, and the specific features utilized in your project. If provider keys are not on file, Vapi will make API requests using its own keys, and the expense is then passed on at-cost to your Vapi account [(1)](
) . Additionally, Vapi charges a flat rate of $0.05 per minute for calls, and if you've used transcription, model, voice, or telephony services, those costs are charged at-cost [(2)](
) . Please review the [Cost Routing](
) and [Pricing](
) documentation for a detailed breakdown of potential costs. If discrepancies persist, it's best to directly contact Vapi's support for a detailed explanation and resolution.