> ## Documentation Index
> Fetch the complete documentation index at: https://developer.buildmarkets.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Order Cancel Request <F>

> How to cancel all remaining quantity on an existing order through the Buildmarkets FIX Gateway.

## Overview

The Order Cancel Request message (MsgType = "F") enables cancellation of all remaining quantity on an existing order within the Buildmarkets FIX Gateway.

## Key Warning

"A cancel request may be rejected if the order is already filled, expired, or in a non-cancellable state." Monitor for either confirmation via Execution Report or denial via Order Cancel Reject.

## Required Fields

| Tag | Field        | Description                                     | Type         |
| --- | ------------ | ----------------------------------------------- | ------------ |
| 1   | Account      | Trading account identifier                      | String       |
| 11  | ClOrdID      | Unique identifier for cancel request            | String       |
| 37  | OrderId      | OrderId from the gateway                        | String       |
| 41  | OrigClOrdID  | ClOrdID of order being cancelled                | String       |
| 48  | SecurityID   | Security identifier (numeric)                   | Numeric      |
| 55  | Symbol       | Security symbol in uppercase                    | String       |
| 60  | TransactTime | Transaction timestamp                           | UTCTimestamp |
| 167 | SecurityType | Type: CS (stock), OPT (option), MLEG (multileg) | String       |

## Optional Fields

| Tag | Field | Description                                      |
| --- | ----- | ------------------------------------------------ |
| 54  | Side  | Must match original order's side (1=Buy, 2=Sell) |

## Message Examples

**Equity Order Cancellation:**

```
8=FIX.4.4|35=F|49=CLIENT1|56=BUILDMARKETS|11=CXL-20260212-001|1=ACC123456789|37=BMKT-78450|41=ORD-20260212-001|55=AAPL|167=CS|54=1|60=20260212-15:00:00.000|10=034|
```

**Option Order Cancellation:**

```
8=FIX.4.4|35=F|49=CLIENT1|56=BUILDMARKETS|11=CXL-20260212-002|1=ACC123456789|37=BMKT-78451|41=ORD-20260212-003|55=AAPL|167=OPT|54=1|60=20260212-15:00:00.000|10=056|
```

**Multileg Order Cancellation:**

```
8=FIX.4.4|35=F|49=CLIENT1|56=BUILDMARKETS|11=CXL-20260212-003|1=ACC123456789|37=BMKT-78460|41=MLEG-20260212-001|55=AAPL|167=MLEG|54=1|60=20260212-15:00:00.000|10=078|
```

## REST Alternatives

* Single-leg: `POST /api/external/cancel?OrderCode={code}&AccountNo={acct}`
* Multi-leg: `POST /api/Order/CancelMultiLegOrder` (JSON body)