---
title: "Apply add-on to customer"
method: POST
path: "/api/add-ons/apply"
tags: ["Add-Ons"]
---

# Apply add-on to customer

`POST /api/add-ons/apply`

Create a one-time charge for a customer. Will be included in the next invoice.

## Request body

- ApplyAddOnDto
  - `addOnId` string, required — Add-on ID
  - `customerId` string, required — Customer ID
  - `subscriptionId` string — Subscription to attach the charge to
  - `amount` number, required — Charge amount
  - `currency` string, required — Currency

## Response `201`

Add-on applied

- AppliedAddOnResponse
  - `id` string, required
  - `addOnId` string, required
  - `customerId` string, required
  - `subscriptionId` string
  - `amount` string, required
  - `currency` string, required
  - `invoiceId` string
  - `createdAt` string, required

## Other responses

- `404` — Add-on, customer, or subscription not found

---

[API](https://skmtc.net/novabilling/apis/novabilling-api.md) · [All operations](https://skmtc.net/novabilling/apis/novabilling-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/novabilling/novabilling-api/revisions/0e449a4e0dc8/schema)