Brokers can have a different price because they have different execution methods.
Some brokers dont even execute your trade in the market and instead just execute your trade on their platform (B Book). This means that they determine their own pricing.
Brokers, like Fair Forex who are A book will execute your trade into the market using a liquidity provider.
We are also a True ECN broker, meaning that our liquidity is like an Ocean. Some brokers could be in the Atlantic Ocean and some could be in the Pacific Ocean. And pricing will be different because liquidity is different.
Our pricing is True market pricing because it is solely determined by the liquidity in our ocean, not by manipulation. Therefore, we always recommend that you use the market watch in MT5 to show the bid ask spread.
We also recommend that you download the free True Bid Ask indicator in the downloads section on your FF portal to show this accurately on the charts.
If you use Trading View, please note that pricing quoted on charts does not include spreads. However we find that we are most alike FXCM for forex, Forex.com for XAUUSD and Currency.com for Indices. On Indices please make sure you chose the correct one i.e. futures or cash/spot.
Obviously pricing will never be exact for the reasons stated so this is just a guide. Always practice on demo first and use proper risk management.