add docs

Author: bryantanderson

fern/snippets/faq-snippet.mdx

@@ -57,4 +57,34 @@ To learn more about Vapi’s pricing, you can visit our [pricing page](/pricing)
     Vapi also has some of the lowest latency & (equally important) highest reliability amongst any other voice AI platform built for developers.
 
   </Accordion>
+
+  <Accordion title="How does Vapi's billing system work?" icon="money" iconType="solid" defaultOpen={false}>
+
+    ### Overview 
+    - Vapi uses a credit-based billing system
+    - Credits are used for all platform services and add-ons
+    - New users receive 10 free credits to start
+    - Credits are stored in your organization's wallet
+
+    ### What are add-ons?
+    Add-ons are platform enhancements that you may purchase. Vapi currently provides the following add-ons:
+
+    | Add-on | Price (credits/month) |
+    |--------|---------------------|
+    | Phone Numbers | 2 |
+    | Reserved Concurrency Lines | 10 |
+    | HIPAA Compliance | 1,000 |
+    | Slack Support | 5,000 |
+
+    Here's how the billing works:
+    - You'll be charged a prorated amount for the remainder of the current billing cycle when you first purchase an add-on
+    - Subsequently, you'll be billed the full amount at the start of each billing cycle (the 1st of each month)
+    - If your credit balance is insufficient to cover the monthly charge, your payment method will automatically be charged for the difference to prevent your balance from going below zero
+    - If you cancel an add-on, you'll receive a prorated refund for the unused portion of the billing cycle. Add-ons can be cancelled at any time through the billing page
+
+    <Warning>
+      If your subscription is frozen at the time of billing (e.g., due to payment issues), all add-ons will be automatically cancelled. You'll need to repurchase them once your subscription is reactivated.
+    </Warning>
+
+  </Accordion>
 </AccordionGroup>