Change the subscription billing interval
Switches the subscription billing interval (e.g. upgrade monthly → annual). Prorated and invoiced immediately; the new-period entitlement lands when that invoice is paid. Clears any scheduled cancellation. No-op if already on the target interval. Not available during impersonation.
Authentication
Your Dial API key, sent as Authorization: Bearer sk_live_...
Request
Optional Unix timestamp (seconds) from a prior preview’s prorationDate. When supplied, the proration is calculated as of that instant so the charged amount matches the previewed quote exactly. Omit to prorate as of now.
Response
Interval change applied (or already on the target interval).