We just hit this exact wall. We required address on the Mews online check-in form, which works well, but the booking engine has no equivalent. The only extra field we can require there is Telephone. That leaves address capture entirely dependent on guests completing online check-in after booking. For a property using check-in to bypass a separate kiosk vendor, having address required at the point of booking would close the loop completely.

In our case, requesting both the customer’s address and tax identification number is essential—especially for non-refundable bookings. In many countries, tax regulations require issuing an invoice at the moment the reservation is charged, and that invoice must include the customer’s complete billing details.
Without this information, we cannot comply with invoicing requirements, and we are forced to request the data manually from each guest afterwards.