---
title: "Link add-ons to a subscription"
method: POST
path: "/subscriptions/{subscriptionId}/add-ons"
tags: ["Subscriptions"]
---

# Link add-ons to a subscription

`POST /subscriptions/{subscriptionId}/add-ons`

## Request

- Base URL: `https://api.helcim.com/v2`
- URL: `https://api.helcim.com/v2/subscriptions/{subscriptionId}/add-ons`
- Auth: none declared. Required headers: `api-token`

Link one or more add-ons to a subscription by subscription id

## Path parameters

- `subscriptionId` integer, required

## Headers

- `api-token` string, required

## Request body

- SubscriptionAddOnCreationReq
  - `addOns` SubscriptionAddOnCreateInner[]: The add-ons linked to the payment plan to apply to the subscription
    - `addOnId` integer, required: The id of the linked plan add-on to apply to the subscription
    - `quantity` integer: The number of duplicates of the indicated add-on to apply to the target subscription. If provided the add-on must support quantity editing to apply the specified quantity.

## Response `201`

Successful linking of add-ons to the subscription. The response body contains the data representation of  all newly linked add-ons.

- SubscriptionAddOnCreationRes
  - `data` BaseSubscriptionAddOn[]
    - `addOnId` integer
    - `name` string
    - `description` string
    - `amount` number, float
    - `firstProcessedNumber` integer
    - `lastProcessedNumber` integer
    - `isActive` string
    - `frequency` string
    - `quantity` integer

## Other responses

- `400`: You are initiating a request with invalid parameter and/or body values.
- `401`: You are not authorized to access this resource. Please ensure that you are authenticated, and that you are using the `api-token` header
- `403`: You do not have permission to access this resource. Please ensure you are both authenticated and that you have the required roles/permissions active.
- `500`: Helcim internal server error encountered.

---

[API](https://skmtc.dev/helcim/apis/recurring-api.md) - [All operations](https://skmtc.dev/helcim/apis/recurring-api/llms.txt) - [OpenAPI document](https://skmtc.dev/helcim/apis/recurring-api/revisions/cd9c0c023548?raw)