# MT5 API error 10030 TRADE_RETCODE_INVALID_FILL

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This is the markdown version of https://openbrokerapi.com/errors/mt5/10030, written from the same records as that page.

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The error, as text you can copy:

```
10030
```

- Kind: Trade server return code
- Where you meet it: Returned by the trade server to the platform
- API: [MetaTrader 5 (Python package and MQL5)](https://openbrokerapi.com/platforms/metatrader-5)
- Status: verified. Source: [mql5.com](https://www.mql5.com/en/docs/constants/errorswarnings/enum_trade_return_codes), checked 2026-09-22.

## What does 10030 mean on the MetaTrader 5 API?

Invalid order filling type: order_send asked for a filling mode the symbol does not allow. The usual cause is a hardcoded ORDER_FILLING_RETURN on a market execution symbol.

## How do I fix 10030?

Read the allowed modes before sending: modes = mt5.symbol_info(symbol).filling_mode. If modes & 1 use ORDER_FILLING_FOK, else if modes & 2 use ORDER_FILLING_IOC, else use ORDER_FILLING_RETURN, which is allowed in every execution mode except market execution. Put the result in type_filling.

## More on the MetaTrader 5 API

- [All MetaTrader 5 API error codes](https://openbrokerapi.com/errors/mt5)
- [MetaTrader 5 API quickstart](https://openbrokerapi.com/platforms/metatrader-5/quickstart): From credentials to a first call on a demo account, step by step.
- [MetaTrader 5 API error codes](https://openbrokerapi.com/errors/mt5): 311 decoded, each with what it means, and the fix where the source gives one.
- [MetaTrader 5 functions](https://openbrokerapi.com/platforms/metatrader-5/functions): 78 documented, each with its signature, arguments, return value and source.
- [MetaTrader 5 API page](https://openbrokerapi.com/platforms/metatrader-5): The full record: access, authentication, limits and the source for each.
- [Claude with MetaTrader 5: a safe, read-first setup](https://openbrokerapi.com/guides/claude-mt5): Guide
- [MetaTrader 5 for Python: which platforms does it run on?](https://openbrokerapi.com/guides/metatrader-5-python-platforms): Guide
- [MT5 trade history to a spreadsheet with Python](https://openbrokerapi.com/guides/mt5-trade-history-to-a-spreadsheet): Guide

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Cite as: MT5 API error 10030 TRADE_RETCODE_INVALID_FILL. Broker API Hub, https://openbrokerapi.com/errors/mt5/10030, newest check 2026-09-22.

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