Originally Posted by
agp423
I can confirm that this is not true. Amex "backdating" just changes the "Member Since" year to the year your first Amex was opened. But when you pull your credit report, your account opened date is when you actually opened that particular account, not the date when your first Amex account. If you don't believe me, get your AAoA, then do a round of apps of Amex card(s). Asking them to "backdate." Get your AAoA again. The second AAoA will be lower.
I have had the opposite experience, where it does change the account opened date. Perhaps this has changed recently?
However, even with backdating, it could lower AAoA anyway. Let's say you have 4 cards, each at 5 years, plus an Amex at 3, with AAoA = (5+5+5+5+3) / 5 = 4.6
Add another Amex and it would be (5+5+5+5+3+3) / 6 = 4.3
Is that what you're seeing or does your actual credit report have a different date for account open?
(Also, the backdating is automatic, not something you need to call for - so perhaps something else is wrong here? Authorized user accounts don't factor into backdating anymore.)