MQL4/MQL5 migration

 
Ladies and gentlemen,
Question:
If a broker supports MT4 / MQL4, will it support MT5 / MQL5, in other words, if my application migrates from MQL4 to MQL5, is this transition transparent from the broker's point of view?
Thank you.
 
  1. Some brokers support MT4 only. Some MT5 only. Some both.
  2. Nothing is transparent. You can't run MQL5 on MT4 terminal. You will have to download the MT5 terminal (assuming your broker supports it.)
  3. Broker can tell which you are using.