The same ticker. Three different names.
TradingView sends XAUUSD. Your broker calls the same instrument GOLD. The order comes back as “Unknown symbol”, and nothing you change in the alert fixes it: the two names simply do not match. A mapping list declares the correspondence once; every alert that follows is translated on the way through.
What the robot already handles on its own
Most rejections blamed on symbol names need no mapping at all.
- xauusd, XAUUSD, XauUsd — case never blocks, on all three platforms.
- OANDA:EURUSD — the exchange prefix is dropped: the alert is read as EURUSD.
- EURUSD.pro, EURUSDm, EURUSD.r — a broker suffix is usually resolved on its own: MT5 also searches by currency pair, MT4 tries the suffixes it knows.
What no robot can guess is a genuinely different name: GOLD for XAUUSD, DJ30 for US30, GER40 for DAX. That is what a mapping is for.
When a list is needed
The right-hand names are examples: every broker has its own, and the same broker can change them from one account type to the next. The only reliable source is your platform's Market Watch.
Create a list, attach it to an account
- Symbol mapping › New list. Name it after your broker: a correspondence only ever makes sense for one broker. Up to ten lists per workspace, shared by all your accounts.
- One line per symbol. On the left, the name as TradingView sends it; on the right, the name exactly as your broker writes it. Copy it from the Market Watch rather than typing it from memory.
XAUUSD -> GOLD US30 -> DJ30
- My accounts › Robot settings › Symbol mapping. Pick the list and save. The account card then shows its name under Mapping. One list can serve several accounts at the same broker.
Check that it works
Send a test alert on the symbol you just mapped and open Alert history: the line must show Executed. If it still comes back as Unknown symbol, compare the two names character by character with the Market Watch: a trailing space or an unexpected suffix is enough.
The full step-by-step, with screenshots, is in the documentation: Symbol mapping guide.
FAQ
Do I have to change my TradingView alerts?
No. The alert keeps the TradingView symbol; the list translates the name on the way through, for every alert that follows.
Is mapping only for MT4?
No: MT4, MT5 and cTrader. Case is resolved on all three; a broker suffix is usually resolved on its own, MT5 also searching by currency pair and MT4 trying the suffixes it knows.
What happens if the name is still unknown?
The platform refuses the order and the alert history shows Unknown symbol. Compare the two names character by character with your Market Watch: a trailing space or an unexpected suffix is enough.
Can one list serve several accounts?
Yes, at the same broker. Lists belong to the workspace, up to ten, and each account picks its own in the robot settings.
One list, a few lines, and the alert goes through.
Free account; symbol mapping is included from Basic, for all three platforms.