> ## Documentation Index
> Fetch the complete documentation index at: https://docs.momentco.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> Configuring automated payment schedules

A **subscription** automates future `next_in_series` payments within the boundaries of a mandate. When `subscription_options` is provided on a `first_in_series` session, the platform schedules and executes recurring collections automatically.

The [mandate](/documentation/collect/payment-sessions/mandates/overview) is the consent ceiling; the subscription runs within it.

<Note>
  Providing `subscription_options` is optional.

  Omitting it creates the mandate but leaves scheduling to the merchant, who must initiate each `next_in_series` payment manually.

  An empty `subscription_options` is valid and creates a subscription with all properties inherited or defaulted from the mandate: `active_period` inherits from `mandate_options.validity_period`, `amount` infers from `mandate_options.amount` or the original session amount, and `scheduled_time` defaults to `00:00`.

  If the mandate has no `validity_period`, the subscription runs indefinitely.
</Note>

<Warning>
  A subscription's `active_period` must fall within the mandate's `validity_period`.

  The platform will not execute a payment that would violate any mandate constraint, regardless of what the subscription schedules.
</Warning>

### Active Period

Defines the date range within which the subscription is active. Payments are only scheduled within this window.

A subscription active throughout 2026:

```json theme={"system"}
{
  "subscription_options": {
    "active_period": {
      "start_date": "2026-01-01",
      "end_date": "2026-12-31"
    }
  }
}
```

If `start_date` is omitted, the subscription starts immediately (or inherits from `mandate_options.validity_period.start_date`). If `end_date` is omitted, it runs indefinitely (or inherits from `mandate_options.validity_period.end_date`).

The active period must fall within `mandate_options.validity_period`. The mandate remains the authorisation ceiling and cannot be exceeded.

<br />

### Amount

The fixed amount in the smallest currency unit collected for each scheduled payment.

Collecting 20.00 ZAR on each scheduled payment:

```json theme={"system"}
{
  "subscription_options": {
    "amount": 2000
  }
}
```

If omitted, the amount is inferred in order from: `mandate_options.amount` (if a fixed amount), then the original session amount.

<br />

### Recurrence

The payment cadence is defined in `mandate_options`, not in `subscription_options`. This ensures the recurrence is part of the customer's consent boundary and is available to providers for deriving implicit period windows.

For `scheduled` and `on_demand` mandates, recurrence is at `mandate_options.recurrence`. For `installment` mandates with `terms.type: periodic`, it is at `mandate_options.terms.recurrence`. In both cases the subscription engine uses the same recurrence to schedule payments.

See [Mandates: Recurrence](/documentation/collect/payment-sessions/mandates/overview#recurrence) for the full reference and examples.

<br />

### Scheduled Time

The time of day at which scheduled collections are executed. Specified in 24-hour `HH:MM` format and evaluated in the timezone set by `mandate_options.timezone`. Defaults to `00:00` if not specified.

Collections executed at 9:00 AM each scheduled day:

```json theme={"system"}
{
  "subscription_options": {
    "scheduled_time": "09:00"
  }
}
```

***

For full configuration examples, see [Subscription Examples](/documentation/collect/payment-sessions/subscriptions/examples).