Originally Posted by
BigLar
Not sure I understand what you're saying here. Sure, BA,AA,US, etc, all have expiration dates, but normally any activity in the account extends the date, so we usually don't worry much about that.
Unless you're saying that transferred-in miles are treated differently than, say, BIS miles, which I don't believe is the case.
SQ miles expire, IIRC in three years, regardless of account activity. There might be exceptions for elites, etc.
DL is notorious for poor award ticket availability and for an award calendar that doesn't work (and sometimes shows availability when it isn't there or when the award itineraries feature horrible schedules and overnight connections). Don't transfer miles to DL unless you are sure you can redeem at reasonable prices in miles for flights you want.