---
search:
  tags:
    - Offsets
    - POST
seo:
  description: >-
    Takes the cost from your balance and orders the credits. The offset starts
    as… Reference for the POST /offsets endpoint in the TrimCarbon Offset API.
sidebar:
  label: Buy offsets
  badge: POST
title: Buy offsets
type: openapi-operation
---
Takes the cost from your balance and orders the credits. The offset starts as `processing`; it becomes `placed` once the credits are retired, usually within minutes. Purchases larger than your account’s review limit wait for our review first. Needs a key with purchase access.

`POST /offsets`

**Request body** (`application/json`, required)

Exactly one of \`kg\` (whole kg, up to 1,000,000) and \`amount\_cents\`, and an optional \`reference\`.

Request body example, By volume:

```json
{
  "kg": 1000,
  "reference": "fleet-2026-09"
}
```

Request body example, By price:

```json
{
  "amount_cents": 5000
}
```

**Responses**

- `201` — The purchase (or, on a retry, the first one).
- `400` — Bad JSON, or a missing or invalid Idempotency-Key.
- `401` — Missing, unknown or revoked API key.
- `402` — \`insufficient\_balance\`: the balance doesn’t cover the purchase. The error has \`balance\_cents\` and \`required\_cents\`.
- `403` — \`api\_access\_inactive\` (the account is suspended or not approved) or \`insufficient\_permissions\` (a read-only key).
- `409` — \`idempotency\_key\_reused\`: the key was used for a different request.
- `422` — \`validation\_error\` (with \`param\`) or \`amount\_too\_small\`.
- `429` — \`rate\_limited\`: wait for the \`Retry-After\` seconds.

Response example, 201:

```json
{
  "object": "offset",
  "id": "off_8Hq2kP0aZr4mXc1vB7nT3yLw",
  "livemode": true,
  "status": "processing",
  "kg": 0,
  "amount_cents": 0,
  "currency": "usd",
  "rate_millicents_per_kg": 4000,
  "requested": {
    "kg": 0,
    "amount_cents": 0
  },
  "reference": "string",
  "certificate_url": "http://example.com",
  "created": "2026-10-08T14:03:12.000Z",
  "placed": "2026-10-08T14:03:12.000Z"
}
```