Hi FT'ers!

I've tried super hard to avoid being That Guy who asks obvious questions when they should've read the site. But I've combed Google, read loads of threads / FAQs and sat on hold with SQ CS for 15 minutes before giving up.

I have a simple question: what order are KF miles used / spent?

For example, let's say I had a balance of 50,000 miles, expiring as follows:

Miles / Date expiring
10,000 - DEC 09
20,000 - FEB 10
20,000 - DEC 10

If I booked a redemption flight costing 15,000 miles today (NOV 09), would that affect my account as follows:
Miles / Date expiring
0 - DEC 09 (totally used by booking
15,000 - FEB 10 (5,000 used by booking. Remainder expire FEB 10)
20,000 - DEC 10

Is that right? Are they used by the order of "first to expire, first" ??

I'm trying to figure out what miles to extend (at 1,200 miles per 10k!!) and what will get used if I make a booking.

Thanks in advance for your help.

- Geoff
London, UK