I think my sibling comment's experiences are somewhat dated. Running one-time payments has been absolutely no problem with ChargeBee for us. It's obviously gear

I think my sibling comment's experiences are somewhat dated. Running one-time payments has been absolutely no problem with ChargeBee for us. It's obviously geared toward subscription businesses, but it has full support for one-time charges as well. No need for any hacks or weird work-arounds. Regarding what pain is left: I'm approaching this from an end-to-end perspective, so answering the question "Even when using ChargeBee, what additional work do we have to do compared to a similar business based in the US?": - You still have to code in UI-level support for multiple currencies. ChargeBee handles the backend. - ChargeBee gives you a nice UI for keeping track of paid and unpaid invoices. Nonetheless, for payments via bank transfer [which your EU business customers will want to use], you still have to manually confirm in ChargeBee that you've received payment. - You still have to supply quarterly MOSS tax returns to your local tax authorities (though ChargeBee does all it can to make that process quick).