Entirely made-up with not much of a system because I don’t want to bother XD
In Elgana, it’s omnia. There’s paper and coins.
Sorcerers, however, have their own little naming system for the coins and paper. I forgot what it was 
I think coins were trinks or something like that.
I use Bars, and Coins.
Both in Silver and Gold.
5 Silver Coins = 1 Gold Coin.
5 Gold Coins = 1 Silver Bar.
5 Silver Bars = 1 Gold Bar.
Coins are about the size of a 5p (UK) . Bars are somewhat 5cm length and 1cm thick. And they are cylindrical in shape.
SD
I’ve been avoiding currency in my world for… ever. xD Mostly because I want them to use actual made-up currency, but I got lazy and didn’t want to do conversions for real money.
Same thing with language. Despite the book being in English (for obvious reasons haha), my characters speak a language called Aklasion but you never see any words in the book because… I just don’t know how to create an actual language. How some writers can do it (I’m looking at you Star Trek with your Klingon 
) is beyond me. 
I must be real lazy then. I just used US currency in story, but with a different name.
Yeah, very creative, Qualeshia…
I would’ve done the same. 
But since mine takes place in the far future where almost everything is obsolete, and it’s not even in the US, it didn’t make sense to use our currency. 
I believe I did create a word for the currency, but I don’t remember what it was. 
It was added a revision or so ago in a scene I had where people were betting on something happening as a joke (like “I bet (whatever money) on that happening”) xD
What’s even more hilarious for me is that my story takes place on a entirely constructed fictional world and my global currency is just American dollars with One Piece flair.
So, yeah…
This topic gave me the kick in the butt I needed to actually sit down and design the coins 
Awesome.