Originally Posted by corporate-wage-slave

If you always travel together, the best arrangement is to have your year end date 6 months apart. Lounges, baggage allowance, the First Wing, seat selection, fast track, premium check-in is all guest-able so by having a 6 month gap you can be more creative over time, for example if you need to take a break from travel for a while. Having the same date is actually the worst option.