Activates the pay schedule for an order. The order must already have pay schedule data configured (via the Update or Create Order endpoint) but not yet started.

If a startOn date is provided, the schedule is deferred to that date — no payment is processed immediately. An invoice is sent to the customer via their configured notification preferences (email/SMS).

If no startOn date is provided and payOnStart is true, the first payment is processed immediately using the stored billing token (or a provided session). A billing token must be attached to the order pay schedule or a pay session must be specified in the start request body.

If no startOn date is provided and payOnStart is false, the schedule is activated today with the first payment due one period from now. An invoice is sent to the customer.

For autopay schedules, a tokenized billing method must be stored before activation. A session can be provided to tokenize a new payment method as part of this request.

Behavior Matrix

The behavior of this endpoint depends on three parameters: autopay (set on the pay schedule), startOn, and payOnStart. Below is a reference for all combinations. The startOn example uses +7 days from today for illustration; any future date works.

Key notes:

• When startOn is provided, no payment is processed regardless of other parameters. An invoice is sent instead.
• When payOnStart is true and startOn is set, the first payment is due on the startOn date (not processed immediately).
• When payOnStart is true and startOn is null, the first payment is processed immediately.
• "1 period" refers to the pay schedule's configured frequency (e.g., 1 month for monthly).