---
title: unsupported_format — Unsupported export format
description: "HTTP 406 unsupported_format: Supported formats are .csv and .zip."
canonical_url: "https://cascades.crscreditapi.com/docs/api/errors/unsupported_format"
doc_version: "1.0.0"
last_updated: "2026-10-09T18:04:24Z"
http_status: 406
source: config/api_error_codes.yml
---

# `unsupported_format` — Unsupported export format

**HTTP 406 Not Acceptable**

Message: "Supported formats are .csv and .zip."

Envelope schema: `ErrorEnvelope` in [openapi.json](https://cascades.crscreditapi.com/openapi.json#/components/schemas/ErrorEnvelope) ([YAML](https://cascades.crscreditapi.com/openapi.yaml)).

## What causes it
- `GET /batches/{id}/exports` was requested with an extension other than `.csv` or `.zip`, or with an `Accept` header that resolved to another format.

## How to fix it
1. Request `/batches/{id}/exports.csv` for the flat results file or `/batches/{id}/exports.zip` for results plus per-row report PDFs. The bare path defaults to CSV.

## Operations that return it
- [GET /batches/{id}/exports.csv](/docs/api/batches/export-batch) — Download flat results CSV
- [GET /batches/{id}/exports.zip](/docs/api/batches/export-batch-zip) — Download structured ZIP of batch results

## Example response

```http
HTTP/1.1 406 Not Acceptable
Content-Type: application/json
```

```json
{
  "error": {
    "code": "unsupported_format",
    "message": "Supported formats are .csv and .zip.",
    "details": [],
    "request_id": "6f1c2a3e-8d4b-4c5e-9f0a-1b2c3d4e5f60",
    "doc_url": "https://cascades.crscreditapi.com/docs/api/errors/unsupported_format"
  }
}
```

## Related
- [/docs/concepts/batches](/docs/concepts/batches)

[All error codes](https://cascades.crscreditapi.com/docs/api/errors.md)

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