It’s not really a fee though - it’s just fairly applying the interest rate. It sounds very fair to me - you disadvantage them no more than you help them if they were on the other size of 0.
But more importantly, a fee is an arbitrary amount of money charged. It might be linked to costs you incurred for the other party, they might be making a profit or a loss on the exchange - at the end of the day it’s just an arbitrary amount of money
It’s not really a fee though - it’s just fairly applying the interest rate. It sounds very fair to me - you disadvantage them no more than you help them if they were on the other size of 0.
But more importantly, a fee is an arbitrary amount of money charged. It might be linked to costs you incurred for the other party, they might be making a profit or a loss on the exchange - at the end of the day it’s just an arbitrary amount of money