Originally Posted by
andywaw
Your statement shows the miles which might expire on September 30, because the bank has no idea if you will continue using your card and cannot assume it.
If you use your card once a month, you are fine and the miles won't expire.
If you don't use your card, the bank wants to stay on the safe side and avoid complaints that the customers haven't been informed about the miles expiration.
Soon on your statements you'll find the number of miles which might expire on December 31, etc.
This could be a correct answer, if you replace “bank” with “Miles & More”. I find no mileage information on my SN Amex statements apart from the number of miles transferred from Amex to M&M each month.
The expiry of miles must be listed on the M&M statement, not the credit card statement, and if the OP is M&M entry level then M&M can indeed not be sure that the credit card will keep adding miles to the account each month. If the holder is FTL, SEN or HON then expiry is a non-issue and thus not shown.