How To Transferring Money From One Character To The Other?

[Strongfat900]

FC Chest can be used to transfer gil and items between characters in the same FC.

If you don't have access to an FC Chest, then you can trade items/gil to someone you trust to hold while you change characters.
Keep in mind there is a limit to the amount of 1m gil that can be transferred between players per each trade window. So transferring large amounts of gil this way is not ideal.

And as was mentioned, if neither of the above options are feasible, you could list an item on the MB for a large amount of gil on one character, and then buy it on the first character to move gil between them... however, you'll be taxed twice this way and some of the gil will go poof. Could also move items this way... but you risk someone else buying up your stock while changing characters.

I don't want to transfer that much money really(around 20k gil). Let's say my character A is in a FC, doesn't it mean that my character B that I want to transfer my money to also needs to join the FC as well?