MetaTrader 5 troubleshooting
How do you fix MT5 error 10014?
MT5 trade server code 10014 means the volume in the request was invalid. Check the actual number of lots sent against the minimum, maximum and volume step for the exact symbol on your broker's server.
1. Read the symbol's volume limits
In Market Watch, right-click the exact symbol and open Specification. Note Minimal volume, Maximal volume and Volume step. MQL5 exposes these as SYMBOL_VOLUME_MIN, SYMBOL_VOLUME_MAX and SYMBOL_VOLUME_STEP. The order request's volume is in lots. A lot's contract size varies by symbol, so do not pass a number of units into a field that expects lots.
2. Check the step as well as the range
Worked example. Suppose the minimum is 0.10 lots, the maximum is 2.00 lots and the step is 0.10 lots. An order for 0.25 lots is inside the range, but it is not a multiple of 0.10. An order for 0.20 meets these three volume rules. That check says nothing about whether the order has enough margin or satisfies the original risk limit.
Compare the submitted lot value with the symbol settings. Decimal precision alone does not establish a match with the step. An EA should compare against the allowed increments with an appropriate floating-point tolerance and log the normalized volume before it sends the request.
3. Keep per-order size separate from overall exposure limits
A broker can also set a same-direction aggregate volume limit for open positions and pending orders. MetaQuotes lists 10034 as the code for hitting a symbol's volume limit. It separately lists 10019 for insufficient funds. An EA developer can run OrderCheck() on the complete demo request to find problems before sending. If the strategy's calculated size is below the symbol minimum, have the EA report that constraint rather than silently increasing the requested size.
Frequently asked questions
Why is 0.01 lot accepted on one symbol but rejected on another?
The broker sets volume constraints per symbol. Open Specification for both exact symbols and compare the minimum, maximum and step.
Can 10014 happen even when I have enough margin?
Yes. Free margin and permitted volume are separate checks. A request can be affordable and still violate a symbol's minimum, maximum or step.
Get help with the diagnosis
Bring the symbol, requested lot size, minimum, maximum and step. Those five values are enough to check the most common invalid-volume cases.
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