# cTrader Open API error code: UNABLE_TO_AMEND_ORDER (135)

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This is the markdown version of https://openbrokerapi.com/errors/ctrader/unable-to-amend-order, written from the same records as that page.

Risk warning: CFDs and spread bets are complex instruments and come with a high risk of losing money rapidly due to leverage. You can lose money on these products, and each provider publishes its own loss figure under FCA rules. You should consider whether you understand how they work and whether you can afford to take the high risk of losing your money. Automated and API trading can amplify losses through bugs, connectivity failures and runaway orders.

The error, as text you can copy:

```
UNABLE_TO_AMEND_ORDER
```

- Code number: `135`
- Kind: Open API error code
- Where you meet it: In an error message sent over the Open API connection, not in an HTTP status
- API: [cTrader Open API](https://openbrokerapi.com/platforms/ctrader)
- Status: verified. Source: [github.com](https://github.com/spotware/openapi-proto-messages/blob/main/OpenApiModelMessages.proto), checked 2026-10-09.

## What does UNABLE_TO_AMEND_ORDER (135) mean on the cTrader API?

The order could not be amended. The file gives no reason. Spotware's own comment on UNABLE_TO_AMEND_ORDER = 135 in the ProtoOAErrorCode enum reads: "Unable to amend order."

## No fix in the source

Spotware's file gives no remedy.

That is all the source says, so this page does not invent a fix. General guidance: [the other open API error codes recorded for cTrader](https://openbrokerapi.com/errors/ctrader#protocol-error-code), the [error lookup](https://openbrokerapi.com/tools/error-lookup) for the exact text of the reply you received.

## More on the cTrader API

- [All cTrader API error codes](https://openbrokerapi.com/errors/ctrader)
- [cTrader API quickstart](https://openbrokerapi.com/platforms/ctrader/quickstart): From credentials to a first call on a demo account, step by step.
- [cTrader API error codes](https://openbrokerapi.com/errors/ctrader): 53 decoded, each with what it means, and the fix where the source gives one.
- [cTrader messages](https://openbrokerapi.com/platforms/ctrader/messages): 49 documented, each with its fields and source.
- [cTrader API page](https://openbrokerapi.com/platforms/ctrader): The full record: access, authentication, limits and the source for each.
- [cTrader Open API with Python](https://openbrokerapi.com/guides/ctrader-open-api-python): Guide

## Licence and how to cite

The records behind this page are all rights reserved. This file is the page itself, at its own address, in another format. It is not part of the CC BY 4.0 downloads listed at https://openbrokerapi.com/data. Quote from it with a link to the page.

Cite as: cTrader Open API error code: UNABLE_TO_AMEND_ORDER (135). Broker API Hub, https://openbrokerapi.com/errors/ctrader/unable-to-amend-order, newest check 2026-10-09.

Where you rely on a single figure, cite the source and the checked date printed beside it as well. Where this page and a broker's own documentation differ, the documentation wins.