---
title: "Send a fax (debits prepaid credits)"
method: POST
path: "/api/v1/faxes"
tags: ["faxes"]
---

# Send a fax (debits prepaid credits)

`POST /api/v1/faxes`

## Request

- Base URL: `https://singlefax.com`
- URL: `https://singlefax.com/api/v1/faxes`
- Auth: one of:
  - API key in header `Authorization`
  - HTTP bearer
  - OAuth 2 (authorization code, authorization URL `https://api.singlefax.com/api/auth/oauth2/authorize`, token URL `https://api.singlefax.com/api/auth/oauth2/token`, scopes: `fax:send`)

## Headers

- `Idempotency-Key` string, required

## Request body

- SendFaxRequest
  - `to` union, required: Destination fax number(s) in E.164
    - string: E.164 destination
    - string[]: One fax order per destination; Checkout is one hold
  - `uploadToken` string
  - `base64` string: Document bytes as base64 (PDF, Word, Excel, PowerPoint, RTF, text, or image)
  - `contentType` string: Optional MIME when sniffing is needed. Allowed: application/pdf, application/msword, application/vnd.openxmlformats-officedocument.wordprocessingml.document, application/rtf, text/rtf, text/plain, application/vnd.ms-excel, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet, application/vnd.ms-powerpoint, application/vnd.openxmlformats-officedocument.presentationml.presentation, image/png, image/jpeg, image/gif, image/webp, image/bmp, image/heic, image/heif, image/tiff
  - `cover` boolean

## Response `200`

Queued fax order

- FaxOrder
  - `id` string, required
  - `ids` string[]: All order ids when sending to multiple destinations
  - `recipientCount` integer
  - `fulfillmentStatus` string, required
  - `paymentStatus` string, required
  - `subtotalCents` integer
  - `taxCents` integer
  - `totalCents` integer
  - `currency` string
  - `billablePages` integer
  - `destinationCountry` string
  - `destinationFaxNumber` string, nullable
  - `createdAt` string, date-time
  - `paymentChannel` string

## Other responses

- `401`: Missing or invalid credentials
- `402`: Insufficient credits
- `403`: Missing fax:send scope
- `409`: Idempotency conflict
- `429`: Rate limited

---

[API](https://skmtc.dev/singlefax/apis/singlefax-api.md) · [All operations](https://skmtc.dev/singlefax/apis/singlefax-api/llms.txt) · [OpenAPI document](https://skmtc.dev/singlefax/apis/singlefax-api/revisions/f6fdbfac1e25?raw)