# Create an invoice item

Creates an invoice item.

Endpoint: POST /invoices/{id}/items
Version: latest
Security: SecretApiKey, JWT

## Path parameters:

  - `id` (string, required)
    ID of the resource.

## Request fields (application/json):

  - `type` (string, required)
    Type of invoice item.
    Enum: "debit", "credit"

  - `description` (string)
    Description of the invoice item.

  - `unitPrice` (number, required)
    Unit price of the invoice item.

  - `quantity` (integer)
    Quantity of the invoice item.

  - `productId` (string,null)
    ID of the product.
    Example: "prod_0YV7DES3WPC5J8JD8QTVNZBZNZ"

  - `periodStartTime` (string,null)
    Date and time when the billing period starts.

  - `periodEndTime` (string,null)
    Date and time when the billing period ends.

  - `periodNumber` (integer,null)
    Billing period number that is associated with the invoice item.
For example, an invoice item for a service is included in billing period number 3.
The invoice item is only applied to billing period number 3.

## Response 401 fields (application/json):

  - `status` (integer)
    HTTP status code.

  - `type` (string)
    Problem type in the form of a [URI](https://tools.ietf.org/html/rfc3986) reference.
It should provide human-readable documentation for the problem type.
When this member is not present, its value is assumed to be "about:blank".

  - `title` (string)
    Short, human-readable summary of the problem type.
Other than for the purposes of localization, this should not change from occurrence to occurrence of the problem.

  - `detail` (string)
    Human-readable explanation that is specific to this occurrence of the problem.

  - `instance` (string)
    URI reference that identifies the specific occurrence of the problem.
It may or may not yield further information if dereferenced.

## Response 422 fields (application/json):

  - `status` (integer)
    HTTP status code.

  - `type` (string)
    Problem type in the form of a [URI](https://tools.ietf.org/html/rfc3986) reference.
It should provide human-readable documentation for the problem type.
When this member is not present, its value is assumed to be "about:blank".

  - `title` (string)
    Short, human-readable summary of the problem type.
Other than for the purposes of localization, this should not change from occurrence to occurrence of the problem.

  - `detail` (string)
    Human-readable explanation that is specific to this occurrence of the problem.

  - `instance` (string)
    URI reference that identifies the specific occurrence of the problem.
It may or may not yield further information if dereferenced.

  - `invalidFields` (array)
    Invalid field details.

  - `invalidFields.field` (string)
    Name of the field.
Dot notation is used for nested object field names.

  - `invalidFields.message` (string)
    Message field.

## Response 429 fields (application/json):

  - `type` (string)
    Problem type in the form of a [URI](https://tools.ietf.org/html/rfc3986) reference.
It should provide human-readable documentation for the problem type.
When this member is not present, its value is assumed to be "about:blank".
    Example: "about:blank"

  - `title` (string)
    Short, human-readable summary of the problem type.
Other than for the purposes of localization, this should not change from occurrence to occurrence of the problem.
    Example: "Rate Limit Exceeded"

  - `status` (integer)
    HTTP status code.

  - `detail` (string)
    Human-readable explanation that is specific to this occurrence of the problem.
    Example: "A request cannot be executed because the user has sent too many requests within a certain period of time"

  - `instance` (string)
    URI reference that identifies the specific occurrence of the problem.
It may or may not yield further information if dereferenced.