Why do online bookings say "pending"?

Pending means manual confirmation is on — online requests wait for you to Confirm or Decline them.

Online bookings arrive as pending because Require manual confirmation (online bookings only) is switched on in Settings → Booking rules → Booking windows (*Available on Plus plan and above*). Each request waits until you click Confirm or Decline — you'll find them in the Pending approvals strip at the top of the Bookings page and under Needs attention on Home. Confirming sends the customer their confirmation; declining cancels the request, emails the customer, and refunds any deposit in full. Switch the setting off if you'd rather online bookings confirm themselves instantly. Related: How do I approve or decline online booking requests?