extendSubscriptionItemFreeTrial()

Extends the free trial for the given Subscription Item.

Returns the updated BillingSubscriptionItem object.

function extendSubscriptionItemFreeTrial(subscriptionItemId: string, params: { extendTo: Date }): Promise<BillingSubscriptionItem>

Parameters

• Name subscriptionItemId
  Type string
  Description
  The ID of the Subscription Item to extend the free trial for.

• Name params
  Type { extendTo: Date; }
  Description
  The parameters for the request.

• Name params.extendTo
  Type Date
  Description
  The date to extend the free trial to. Must be in the future and not more than 365 days from the current trial end date.

Usage

const response = await clerkClient.billing.extendSubscriptionItemFreeTrial('subi_123', {
  extendTo: new Date('2026-12-31'),
})

Backend API (BAPI) endpoint

This method in the SDK is a wrapper around the BAPI endpoint POST /billing/subscription_items/{subscription_item_id}/extend_free_trial. See the BAPI reference for more information.