MQL4 ERR_TRADE_HEDGE_PROHIBITED

MQL4 error 149: hedging is prohibited on the account

MQL4 error 149 hedge prohibited maps to ERR_TRADE_HEDGE_PROHIBITED: an opposite order is prohibited when hedging is disabled. The account or server rules do not allow the new order to create opposite exposure on the same symbol. Capture GetLastError immediately after the failed call, correct the cause, and retry only when the condition can change.

HedgePolicyDiagnostic.mq4.mq4
#property strict
#property script_show_inputs

input double Lots = 0.10;
input int Slippage = 3;

void OnStart()
  {
   if(!IsTradeAllowed())
     {
      Print("Trading is not currently allowed or the trade context is busy.");
      return;
     }

   RefreshRates();
   double price = NormalizeDouble(Ask, Digits);
   ResetLastError();
   int ticket = OrderSend(Symbol(), OP_BUY, Lots, price, Slippage,
                          0, 0, "diagnostic", 0, 0, clrNONE);

   if(ticket >= 0)
     {
      Print("Order opened. Ticket ", ticket);
      return;
     }

   int error_code = GetLastError();
   Print("OrderSend failed. error=", error_code,
         " symbol=", Symbol(), " lots=", DoubleToString(Lots, 2),
         " ask=", DoubleToString(price, Digits));
  }
  • Official meaning: an opposite order is prohibited when hedging is disabled
  • Read the failed API return value first
  • Capture GetLastError immediately
  • Retry only when the condition can change

What MQL4 error 149 means

The official MQL4 runtime table names error 149 ERR_TRADE_HEDGE_PROHIBITED and defines it as “an opposite order is prohibited when hedging is disabled.” The account or server rules do not allow the new order to create opposite exposure on the same symbol.

The error number is evidence about one failed call, not a diagnosis of the whole EA. Read the API sentinel first, then call GetLastError immediately because that function returns the current _LastError value and resets it.

Check these conditions before editing the strategy

Start with the inputs and external state that existed at the failure point. A later log entry or a successful call can overwrite the useful context.

  • The account uses a rule set that prohibits hedged positions
  • The EA sends an opposite order instead of reducing or closing exposure
  • Two strategies create conflicting positions on the same symbol
  • Backtest account assumptions differ from the live account rules

Fix the cause, then choose a retry policy

Do not retry the prohibited order. The account rule or position structure must change first.

Keep the original trading and risk rules intact. A workaround that widens stops, increases volume, changes an account setting, or ignores a failed return value can hide the symptom while changing the system.

CheckAction
The account uses a rule set that prohibits hedged positionsConfirm the account’s hedging policy with the broker.
The EA sends an opposite order instead of reducing or closing exposureChange the position-management design only if netting behavior matches the specification.
Two strategies create conflicting positions on the same symbolCoordinate strategy exposure before sending an opposite order.
Backtest account assumptions differ from the live account rulesTest against an account type with the same rules as production.

Review the complete example

The script logs the rejected request. Source changes cannot override an account or server hedging policy, so the execution design must match the target account.

The example improves validation and logging. It does not prove the operation will be accepted by a broker or behave safely in live trading.

HedgePolicyDiagnostic.mq4.mq4
#property strict
#property script_show_inputs

input double Lots = 0.10;
input int Slippage = 3;

void OnStart()
  {
   if(!IsTradeAllowed())
     {
      Print("Trading is not currently allowed or the trade context is busy.");
      return;
     }

   RefreshRates();
   double price = NormalizeDouble(Ask, Digits);
   ResetLastError();
   int ticket = OrderSend(Symbol(), OP_BUY, Lots, price, Slippage,
                          0, 0, "diagnostic", 0, 0, clrNONE);

   if(ticket >= 0)
     {
      Print("Order opened. Ticket ", ticket);
      return;
     }

   int error_code = GetLastError();
   Print("OrderSend failed. error=", error_code,
         " symbol=", Symbol(), " lots=", DoubleToString(Lots, 2),
         " ask=", DoubleToString(price, Digits));
  }
Where Pineify fits

Move from the rule to editable MQL4 source

Pineify can generate or revise one self-contained .mq4 file with MQL4-specific reference context. Its independent static checker returns MetaEditor diagnostics so you can repair source issues before testing in your own MT4 environment.

Open MQL4 Coding Agent

Static diagnostics do not prove runtime behavior, backtest results, broker compatibility, or live-trading safety.

Pineify MQL4 Coding Agent with MQL4 selected and an editable MetaTrader 4 code artifact

A practical workflow

  1. 1

    Confirm the failed call

    Check the API return value before interpreting an error number from the log.

  2. 2

    Capture the error once

    Call GetLastError immediately and record error 149, symbol, prices, volume, ticket, and terminal state relevant to the operation.

  3. 3

    Correct the triggering condition

    Confirm the account’s hedging policy with the broker.

  4. 4

    Retest in the target environment

    Compile the revised source, then test with the same MT4 build, broker, symbol, account permissions, and market state.

Frequently asked questions

What does MQL4 error 149 hedge prohibited mean?

ERR_TRADE_HEDGE_PROHIBITED means an opposite order is prohibited when hedging is disabled. The code should still identify which API returned failure and log the inputs used for that call.

What usually causes MQL4 error 149?

The account uses a rule set that prohibits hedged positions The EA sends an opposite order instead of reducing or closing exposure Two strategies create conflicting positions on the same symbol Backtest account assumptions differ from the live account rules

Should an EA retry after error 149?

Do not retry the prohibited order. The account rule or position structure must change first.

Why should GetLastError be called immediately?

It reports the current _LastError value and resets it. Other operations can change the error state, so a delayed read may describe the wrong call.

Can Pineify fix MQL4 error 149?

Pineify can revise a self-contained .mq4 file, add validation and error logging, and return static MetaEditor diagnostics. It cannot prove broker acceptance, account permissions, market availability, or live execution.

Last verified against the linked official references on . Compile and test the final source in the MetaTrader 4 build, broker, symbol, and account environment you plan to use.

Continue with one reviewable MQL4 file

Define the requirement, inspect the generated source, repair diagnostics, and test the behavior in your own MT4 environment.

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