Originally Posted by
sdsearch
It's possible you may have to keep them until at least early 2019 then. Due to their interpretation of the consumer credit act, these days most banks don't allow any upgrades to cards that you've had for less than a year, and technically any HH card converted from Citi you've had as an Amex for much less than a year.
That also had occurred to me, but then again, the open date transferred along with the card, so that puts them at 10/14 and 10/15.