Your card expires at the end of the month after the end of your year, to allow BA time to send you a new card. The reason your card expires an 'extra' year later, is that your membership of the BAEC is valid until Aug 2014. Membership in the BAEC is valid for the rest of the year in which it is achieved, and the whole of the following year. Therefore, having 'achieved' status in 2012, your membership lasts until the end of this year (your date being Jul '13) and until the end of the following year too...

Hope this makes sense...

Oh - and welcome...!