Stripe handles USD/EUR card payments globally and is the default for SaaS billing (webhook infrastructure, subscription management, invoicing all built-in). However, Stripe does not support BDT direct bank transfer (the dominant payment method for BD businesses). A BD-local provider (e.g. SSLCommerz, ShurjoPay, bKash Business) is needed to serve BD clients. The billing system architecture (D-12) must accommodate both. Seat-based billing for audit firm team members is a separate sub-decision to be confirmed before build starts.