HELP - Premium Service Centre Booking

Hello, my husband’s FLR runs out on 02/12/18 and we want to book his premium service appt this week hopefully for beginning of November. However his passport is currently with the US embassy for renewal so when we get it back it will have a different number to the one that we book the appointment with, is there anyway of changing this detail once the appointment it booked or will we have to wait until we get the passport back to book the appointment? Many thanks for any advice

Hello, my husband’s FLR runs out on 02/12/18 and we want to book his premium service appt this week hopefully for beginning of November. However his passport is currently with the US embassy for renewal so when we get it back it will have a different number to the one that we book the appointment with, is there anyway of changing this detail once the appointment it booked or will we have to wait until we get the passport back to book the appointment? Many thanks for any advice

The system is supposed to be changing in a few weeks (we don't yet know exactly what to) so you'll probably not find anything  available at all. But you should wait until you get the passport back.