Overview

Update an existing subscription. You can modify various attributes like metadata, shipping address, or auto-renewal settings.

Example: Update a subscription's shipping address when a customer moves to a new location.

Conditional Requirements

Condition	Required Fields
`collection_method=charge_automatically`	`source_id`
`plan_id` is set (plan change)	`proration_behavior`, `payment_behavior`, `billing_cycle_anchor`
`plan_id` without `plan_old_provider_id`	`plan_id` required
`end_date` is set	Must be a Unix timestamp >= current period end
`auto_renew` is set	Cannot also change `plan_id` in the same request; value must differ from current subscription state (cannot set `auto_renew=1` if already auto-renewing, or `auto_renew=0` if already not auto-renewing)