Yes they can. I have designed an entire multi-floor apartment in Ireland without ever seeing the property in person. It is incredibly costly to hire an interior designer overseas and so hiring a South African interior designer virtually/via Zoom can save you thousands. All I need to know is 5-10 reliable, quality home decor shops for your city (or country if ordering online) and I can specify exact items for your interior.  If you still have an SA bank account then payment is easy. I also offer payment via Paypal for international clients.