Apply a coupon to a subscription

Applies a coupon (couponId) or a promotion code the customer gave (promotionCode) to the subscription from now on: it discounts the subscription's next invoices for the coupon's duration, counted in the subscription's billing periods. Promotion codes are checked against their restrictions; the redemption counts when the next invoice is paid (at once for a trial). End a discount with discounts.delete. Emits discount.created and subscription.updated.

At a glance

REST: POST /api/v1/subscriptions/{id}/discounts
MCP tool: subscriptions_discounts_create
Operation ID: subscriptions.discounts.create
Scope: Brand
Permission: subscriptions:write
Risk tier: financial
Dry run: Supported (send Ownrecord-Dry-Run: true)
Idempotency: Idempotency-Key required
Modes: Test and live
Authentication: API key with the subscriptions:write scope
Since: M5

Request

Path parameters

Field	Type	Description
`id`	`sub_…` ID

Body

A JSON object (Content-Type: application/json):

Field	Type	Required	Description
`couponId`	`cpn_…` ID	No
`promotionCode`	string	No	A promotion code as the customer typed it (case doesn't matter).

Response

201 Created with a JSON object:

Field	Type	Description
`id`	`sub_…` ID
`object`	`"subscription"`
`livemode`	boolean
`entityId`	`ent_…` ID
`brandId`	`brd_…` ID
`customerId`	`cus_…` ID
`status`	one of `incomplete`, `incomplete_expired`, `trialing`, `active`, `past_due`, `unpaid`, `paused`, `canceled`	`incomplete` (waiting for the first payment, 23 hours), `trialing`, `active`, `past_due`, `unpaid`, `paused`, `canceled` or `incomplete_expired` (spec §16.1).
`items`	array of object
`items[].id`	`si_…` ID
`items[].priceId`	`price_…` ID
`items[].productId`	`prod_…` ID
`items[].quantity`	integer
`items[].createdAt`	date-time
`currency`	string
`mrr`	money or null	The items' monthly recurring amount (licensed items, before discounts and tax).
`collectionMethod`	one of `charge_automatically`, `send_invoice`
`daysUntilDue`	integer or null
`defaultPaymentMethodId`	`pm_…` ID or null
`billingCycleAnchor`	date-time
`currentPeriodStart`	date-time
`currentPeriodEnd`	date-time
`trialStart`	date-time or null
`trialEnd`	date-time or null
`trialEndBehavior`	one of `convert`, `cancel_if_no_payment_method`, `pause_if_no_payment_method`
`cancelAtPeriodEnd`	boolean
`cancelAt`	date-time or null
`canceledAt`	date-time or null
`endedAt`	date-time or null
`cancellation`	object or null
`pause`	object or null
`discountIds`	array of `disc_…` ID
`pendingUpdate`	object or null
`latestInvoiceId`	`inv_…` ID or null
`incompleteExpiresAt`	date-time or null
`testClockId`	`clk_…` ID or null
`dunning`	object or null	Dunning (§16.10) while past due or unpaid; null otherwise.
`usageThreshold`	money or null	Unbilled metered usage worth this much is invoiced at once (spec §16.7).
`entitlementGraceUntil`	date-time or null
`metadata`	object
`version`	integer
`createdAt`	date-time
`updatedAt`	date-time

Examples

Apply the customer's promotion code

HTTP

POST /api/v1/subscriptions/sub_01m4tx5nj8emwbyf7y9vcf47z5/discounts
Authorization: Bearer or_test_…
Idempotency-Key: 3f1c9a52-7d0e-4b8f-9a61-0c2d5e8b7f14
Content-Type: application/json

{
  "promotionCode": "LAUNCH50"
}

Response (201):

JSON

{
  "id": "sub_01m4tx5nj8emwbyf7y9vcf47z5",
  "object": "subscription",
  "livemode": false,
  "entityId": "ent_01m4tx5nj8emwbyf7y9vcf47zm",
  "brandId": "brd_01m4tx5nj8emwbyf7y9vcf47x4",
  "customerId": "cus_01m4tx5nj8emwbyf7y9vcf47z4",
  "status": "active",
  "items": [
    {
      "id": "si_01m4tx5nj8emwbyf7y9vcf47za",
      "priceId": "price_01m4tx5nj8emwbyf7y9vcf47y2",
      "productId": "prod_01m4tx5nj8emwbyf7y9vcf47y0",
      "quantity": 3,
      "createdAt": "2026-10-13T12:00:00.000Z"
    },
    {
      "id": "si_01m4tx5nj8emwbyf7y9vcf47zb",
      "priceId": "price_01m4tx5nj8emwbyf7y9vcf47y9",
      "productId": "prod_01m4tx5nj8emwbyf7y9vcf47y1",
      "quantity": 1,
      "createdAt": "2026-10-13T12:00:00.000Z"
    }
  ],
  "currency": "EUR",
  "mrr": {
    "amount": "87000000",
    "currency": "EUR"
  },
  "collectionMethod": "charge_automatically",
  "daysUntilDue": null,
  "defaultPaymentMethodId": "pm_01m4tx5nj8emwbyf7y9vcf47zd",
  "billingCycleAnchor": "2026-10-13T12:00:00.000Z",
  "currentPeriodStart": "2026-10-13T12:00:00.000Z",
  "currentPeriodEnd": "2026-11-13T12:00:00.000Z",
  "trialStart": null,
  "trialEnd": null,
  "trialEndBehavior": "convert",
  "cancelAtPeriodEnd": false,
  "cancelAt": null,
  "canceledAt": null,
  "endedAt": null,
  "cancellation": null,
  "pause": null,
  "discountIds": ["disc_01m4tx5nj8emwbyf7y9vcf47z3"],
  "pendingUpdate": null,
  "latestInvoiceId": "inv_01m4tx5nj8emwbyf7y9vcf47zn",
  "incompleteExpiresAt": null,
  "testClockId": null,
  "dunning": null,
  "usageThreshold": null,
  "entitlementGraceUntil": null,
  "metadata": {
    "crm_account": "A-1042"
  },
  "version": 3,
  "createdAt": "2026-10-13T12:00:00.000Z",
  "updatedAt": "2026-10-20T09:00:00.000Z"
}

Errors

Code	HTTP status	When	What to do
`validation_failed`	400	A field is malformed or out of range.	Fix the fields listed in `details.issues` and send the request again.
`resource_not_found`	404	No subscription (or customer, price, coupon) with this ID is visible to the request.	Check the ID and that your credentials are scoped to the right organization, entity, brand and mode.
`subscription_status_invalid`	409	The subscription's status doesn't allow this (spec §16.1): see `details.reason`.	Check `details.status`: items change only while trialing, active or past due; pausing needs an active subscription and resuming a paused one; reactivating needs a cancellation scheduled for the period end; canceled and expired subscriptions don't change.
`coupon_not_redeemable`	409	The coupon is archived, expired or used up.	Check `details.reason`: reactivate an archived coupon, or create a new coupon when it expired or reached its redemption limit.
`promotion_code_not_redeemable`	409	The promotion code can't be used (`details.reason`).	Check `details.reason` and tell the customer: the code may have expired, be used up, belong to another customer, need a larger purchase or be for first-time customers only.
`discount_already_applied`	409	The coupon is already applied to this subscription.	End the existing discount first (`discounts.delete`), or apply a different coupon. The same coupon doesn't stack with itself.
`permission_denied`	403	The credentials can't change this brand's subscriptions (`subscriptions:write`).	Ask an organization owner or admin for a role or scope that allows this action.

It can also return these common errors: api_version_unsupported, invalid_json, unsupported_media_type, authentication_required, api_key_invalid, scope_required, idempotency_key_required, idempotency_key_reused, idempotency_in_progress, approval_required, approval_rejected, approval_expired, stale_approval, approval_policy_denied, rate_limited, internal_error.

At a glance#

Request#

Path parameters#

Body#

Response#

Examples#

Apply the customer's promotion code#

Errors#