It would be helpful if we could associate a transaction fee to an invoice. This is for invoices that are not done within the Moxie platform using Stripe. For example I sometimes get $15 wire transfer fees or percentage fees from PayPal or GoCardless. I create the expense separately but it would be good if I could link it to an invoice specifically just to know where it came from. I can associate expense to a client but not a payment or invoice.