I do not have any challenges within Zoho Books, but sometimes if you want to change the currencies for customers, that can be a bit tricky, especially if you want to issue different invoices in different currencies, maybe even for the same customer, that's the only thing. It's not easy because there's a standard currency created when you create the customer in CRM, and using it in Zoho Books is simple; however, changing that isn't easy anymore as you would have to create a new customer entry inside Zoho Books that runs on a different currency.
