Magic Number
Also known as: EA identifier, order tag
What is it?
A magic number is a simple numeric tag that an Expert Advisor (an automated trading robot inside MetaTrader) stamps onto every order it places. It does not affect the trade's price or size; it is purely a label, like writing your initials on your lunch in a shared fridge so nobody else touches it. The reason it exists is that one MetaTrader account often has several things placing trades at the same time: maybe two different robots, plus a signal connector, plus you trading by hand. They all share the same list of open positions.
Without a way to tell whose trade is whose, one robot could close or modify a position that actually belongs to another, causing chaos. The magic number solves this by giving each automated source its own unique tag. When a robot wants to manage its trades, it looks only at orders carrying its own number and leaves everything else alone. For a beginner running a single ready-made tool, this usually happens automatically behind the scenes, so you may never set one by hand.
But the moment you run more than one automation on the same account, assigning each a distinct magic number becomes essential, because reusing the same number across two systems is a classic mistake that lets them accidentally interfere with one another. In short, it is the bookkeeping that keeps multiple automations, and your own manual trades, cleanly separated on a single account.
Why it matters: Without unique magic numbers, multiple EAs or a connector and a manual trader would step on each other's positions.
Correct tagging prevents automations from interfering with each other's trades.
Real-world example
Two EAs on the same account use different magic numbers, so each only modifies and closes the trades it opened.
How SignalBots handles it
SignalBots' connector tags its orders so its trades stay cleanly separated from your manual or other EA positions.
Pro tip
Assign a distinct magic number to every automated source on an account, including your connector, to keep their trades separate.
Common pitfalls
Running two strategies with the same magic number, so one closes or modifies the other's positions by accident.
Frequently asked questions
Why do automated tools need a magic number?
So each one manages only its own orders. On a shared account, missing or duplicate magic numbers let different systems close or modify each other's trades by mistake.
Do I have to set the magic number myself?
Usually not for a single ready-made tool, which sets one automatically. You only need to assign them deliberately when you run several automations on the same account.
What happens if two robots share the same magic number?
They can no longer tell their trades apart, so one may close or adjust the other's positions. Always give each automated source its own distinct number to prevent this.
Does a magic number change my trade's outcome?
No. It is purely an internal label for organising orders. It has no effect on entry price, size, stop, target, or how the trade performs in the market.
Can I trade manually on the same account as a tagged robot?
Yes. Your manual trades carry no robot tag, so an automation set to manage only its own magic number will leave your hand-placed trades untouched.