MT5 error 4756: trade request failed.

Stops too close to the price (invalid stops, error 10016)

One possible cause of a failed request. Every symbol has a stops level: a minimum distance, in points, that your SL and TP must keep from the current price. If your stop lands inside it, the broker rejects the order. Gold is the classic offender: the stops level on XAUUSD is often wide, and when the spread spikes, a stop that was valid a minute ago falls inside the forbidden zone.

Real support case: a client trading XAUUSD was getting 4756/10016 on every signal. His alerts carried no TP/SL at all, but MT5 had kept old EA inputs on the chart that placed stops inside the broker's stops level for gold during a high-spread window. Setting the SL/TP override inputs to 0 in F7 fixed it on the spot.

Lot size outside the symbol's min / max / step

Every symbol defines a minimum volume, a maximum volume and a volume step. A lot below the minimum, above the maximum, or off the step (0.005 on a 0.01-step symbol) is rejected. This bites alert users who hardcode a lot that works on one symbol but not on another: indices and crypto CFDs have very different rules from forex pairs.

Market closed or quotes paused

If the alert fires while the market is closed (weekend, holiday) or while your broker pauses quoting (common around the 00:00 server-time rollover and during major news), the order is rejected. Check the time of the last tick in Market Watch: if it is frozen, nothing will execute until quotes resume.

For automated setups this is a retry problem, not a configuration problem: a bridge or EA with bounded retries will re-send the order once the market reopens instead of dropping the signal.

Insufficient margin

The broker calculates the margin needed for the position at your leverage and rejects the order if your free margin cannot cover it. Open Toolbox → Trade and compare Free margin against the position you are trying to open. The fix is a smaller lot, higher leverage (if your broker and ruleset allow it), or closing other positions first. On prop-firm accounts, remember the drawdown rules sit on top of plain margin math.

Requote: the price moved

Between your terminal sending the order and the broker executing it, the price moved beyond the allowed deviation, so the broker declines and offers a new price. It happens in fast markets and around news. The practical fixes: allow a larger deviation/slippage in the order settings, use market execution where the broker supports it, and retry, a single requote is normal in a volatile spike.

The alert, not the broker, sent something impossible

An incorrect symbol, unsupported volume or wrong SL/TP units can cause a request to fail. Compare the alert with the field reference and inspect the EA log before attributing the cause to the broker.

The fastest way to rule the payload in or out: paste your alert message into the free webhook tester. It validates the schema and shows you exactly what the bridge would send to MT5, before anything reaches your broker.