---
title: "Add a line item to an invoice"
method: POST
path: "/public-api/v1/invoices/{invoice_id}/invoice_items"
tags: ["Invoices"]
---

# Add a line item to an invoice

`POST /public-api/v1/invoices/{invoice_id}/invoice_items`

## Request

- Base URL: `https://app.hellobonsai.com`
- URL: `https://app.hellobonsai.com/public-api/v1/invoices/{invoice_id}/invoice_items`
- Auth: one of:
  - OAuth 2
    - Authorization code: `https://app.hellobonsai.com/oauth/authorize`
    - Token URL: `https://app.hellobonsai.com/oauth/token`
  - HTTP bearer

Adds one line item to an invoice and recalculates its total.

Only invoices that have not been paid for work here. An invoice that is
paid, partially paid, or has a payment in progress is closed to changes
and returns `403`.

## Request body

- object
  - `invoice_item` object, required
    - `name` string, required: Line item name, as the client will see it. Required.
    - `description` string: Longer description shown beneath the name.
    - `amount` string, required: Quantity billed, as a decimal string. Required, and cannot be negative.
    - `rate` string, required: Price per unit, as a decimal string. Required, and cannot be negative.
    - `unit_type` 'flat' | 'per_hour' | 'per_day' | 'per_item' | 'per_word' | 'per_week' | 'per_month' | 'per_year' | 'per_quarter': What the rate is charged per. Defaults to `flat`.

## Response `201`

The line item was added and the invoice total recalculated.

- object
  - `data` InvoiceItem, required: A single line on an invoice: what you are billing for, how much of it, and at what rate.
    - `id` integer, required: Unique identifier for the line item.
    - `name` string, nullable, required: Line item name, as it appears on the invoice.
    - `description` string, nullable, required: Longer description shown beneath the name, or `null`.
    - `amount` string, nullable, required: Quantity billed, as a decimal string.
    - `rate` string, nullable, required: Price per unit, as a decimal string in the invoice currency.
    - `unit_type` 'flat' | 'per_hour' | 'per_day' | 'per_item' | 'per_word' | 'per_week' | 'per_month' | 'per_year' | 'per_quarter' | 'null', nullable, required: What the rate is charged per. Defaults to `flat`.
    - `total` string, required: `amount` multiplied by `rate`, rounded, as a decimal string.
  - `meta` Meta, required: Metadata returned alongside every single-resource response.
    - `request_id` string, required: Identifier for this request. Quote it when contacting support about a specific call.

## Other responses

- `400`: The request body is missing its `invoice_item` wrapper.
- `401`: The access token is missing, expired or invalid.
- `403`: This token is not allowed to edit invoices, or the invoice is paid, partially paid, or has a payment in progress and can no longer be changed.
- `404`: No invoice with that id that this token can see.
- `422`: The line item could not be saved — `name`, `amount` or `rate` is missing, `unit_type` is not one of the listed values, or `amount` or `rate` is negative.
- `429`: Rate limit exceeded. Wait at least `Retry-After` seconds before trying again.

---

[API](https://skmtc.dev/hellobonsai/apis/bonsai-api.md) - [All operations](https://skmtc.dev/hellobonsai/apis/bonsai-api/llms.txt) - [OpenAPI document](https://skmtc.dev/hellobonsai/apis/bonsai-api/revisions/abf12ed6a8d3?raw)