# Backend `BillingSubscriptionItem` object

The `BillingSubscriptionItem` object is similar to the [BillingSubscriptionItemResource](/content/docs/nextjs/reference/types/billing-subscription-item-resource/index.html) object as it holds information about a subscription item, as well as methods for managing it. However, the `BillingSubscriptionItem` object is different in that it is used in the [Backend API⁠](/content/docs/reference/backend-api/tag/billing/GET/billing/subscription_items/index.html) and is not directly accessible from the Frontend API.

## Properties

- **Name**: `amount`  **Type**: `undefined | BillingMoneyAmount`  **Description**: The current amount for the Subscription Item.
- **Name**: `canceledAt`  **Type**: `null | number`  **Description**: The Unix timestamp (milliseconds) of when the Subscription Item was canceled.
- **Name**: `createdAt`  **Type**: `number`  **Description**: The Unix timestamp (milliseconds) of when the Subscription Item was created.
- **Name**: `endedAt`  **Type**: `null | number`  **Description**: The Unix timestamp (milliseconds) of when the Subscription Item ended.
- **Name**: `id`  **Type**: `string`  **Description**: The unique identifier for the Subscription Item.
- **Name**: `instanceId`  **Type**: `string`  **Description**: The ID of the instance this Subscription Item belongs to.
- **Name**: `isFreeTrial`  **Type**: `boolean`  **Description**: Whether this Subscription Item is currently in a free trial period.
- **Name**: `lifetimePaid?`  **Type**: [BillingMoneyAmount](/content/docs/nextjs/reference/types/billing-money-amount/index.html)  **Description**: The lifetime amount paid for this Subscription Item.
- **Name**: `nextPayment`  **Type**: `undefined | null | { amount: BillingMoneyAmount; date: number; perUnitTotals?: BillingPerUnitTotal[]; totals?: BillingTotals; }`  **Description**: Information about the next scheduled payment for this Subscription Item.
  - **Name**: `nextPayment.amount`  **Type**: [BillingMoneyAmount](/content/docs/nextjs/reference/types/billing-money-amount/index.html)  **Description**: The amount of the next payment.
  - **Name**: `nextPayment.date`  **Type**: `number`  **Description**: The Unix timestamp (milliseconds) of when the next payment is scheduled.
  - **Name**: `nextPayment.perUnitTotals?`  **Type**: `BillingPerUnitTotal[]`  **Description**: The per-unit cost breakdown for the next payment.
  - **Name**: `nextPayment.totals?`  **Type**: [BillingTotals](/content/docs/nextjs/reference/types/billing-totals/index.html)  **Description**: The full cost breakdown for the next payment.
- **Name**: `pastDueAt`  **Type**: `null | number`  **Description**: The Unix timestamp (milliseconds) of when the Subscription Item became past due.
- **Name**: `payerId`  **Type**: `undefined | string`  **Description**: The ID of the payer for this Subscription Item.
- **Name**: `periodEnd`  **Type**: `null | number`  **Description**: The Unix timestamp (milliseconds) of when the current period ends.
- **Name**: `periodStart`  **Type**: `number`  **Description**: The Unix timestamp (milliseconds) of when the current period starts.
- **Name**: `plan`  **Type**: `null | BillingPlan`  **Description**: The Plan associated with this Subscription Item.
- **Name**: `planId`  **Type**: `null | string`  **Description**: The ID of the Plan associated with this Subscription Item.
- **Name**: `planPeriod`  **Type**: `