Can I choose how customers pay online — bank transfer, card, or both?

Yes. Online payments has two switches, Bank transfer and Card, both on to start; at least one always stays on, and the last one on says why it can't be turned off. The choice applies when your customer pays, on every unpaid invoice: the pay page offers only what is on, and a request for a way you turned off is refused. Invoices already open on your own Stripe page, and your Stripe contracts, change to match when you flip a switch; an open Square invoice keeps the ways it was created with, and DeskOps names it so you can change it in Square. Bank transfer is the lowest cost, with DeskOps's 0.4% fee capped at $100; card processing fees apply to cards. With Card off, no new cards can be saved and no new automatic payments set up, while automatic payments customers already agreed to keep running until you or they stop them.