Congrats on the success thus far!
It's always frustrating when you get a ding to your score while using credit responsibly and trying to build... But it happens. It'll become less of a ding with time, and with a faster bounce-back. Your AAoA is a big factor right now. Just be patient and only open a new card every 3-6 months at the soonest, and you'll get there!
@AnonymalousIntellectually it all makes sense. 
Their list is certainly accurate, which my mind reads it as "we really aren't interested in newish, thin files right now, sorry". BUT, though they didn't send a letter (kudos to FNBO for doing that just for a prequal) Citi no doubt rejected the prequal for the same reasons, but given the APR and SL, really liked the file under the scrutiny of a real app, so you're right, I suppose the reasons for prequal rejections mean little (which is probably why other banks dont provide them.) Plus the card I'd actually app for isn't their core cards, so the UW might not be the same, either. (better or worse, though, hard to say.)
Good advice, though, I wouldn't be doing anything before July to get 3 months/statements at the very minimum on Citi, and would also put me at 1.5 years on oldest account (Ironically, that puts me at the original "every 6 months" at that point lol.) I'll try the prequal again at that time and see what it says.
@SUPERSQUIDWow, they flag you for too many accounts with balances when less than 1/4 of them do? A dream of mine is to get to the point where I have a high enough CL and enough open accounts that I can just use a few and pay them automatically when the statement is due like normal people who use credit cards instead of micromanaging them and paying them in advance, and worrying about if pending charges will post at the wrong time to make the statement cut, but it sounds like they treat anything but AZEO as a negative!
@uncredited wrote:
A dream of mine is to get to the point where I have a high enough CL and enough open accounts that I can just use a few and pay them automatically when the statement is due like normal people who use credit cards instead of micromanaging them and paying them in advance, and worrying about if pending charges will post at the wrong time to make the statement cut, but it sounds like they treat anything but AZEO as a negative!
I'm not sure what normal people do but a better payment system would be to setup autopay for the monthly minimum and then once a month after the minimum’s pay out set down and make a second payment for the remainder or a large chunk if your still in payoff mode.
That way you never miss a payment, and you have the flexibility to carry a balance on a card if need be. The only thing to figure out is what your minimums are and set your due dates accordingly.
Excessive worrying over anything is bad for your health especially finances and politics. Best to setup a simple system that you can forget for most of the month.
Here's a general question for all:. Disco closes on the 24th, Citi closes on the 3rd. My intention is to make the disco the zero and Citi the one reporting a balance. Right now disco has the reported balance from last month. Citi is the new account showing on all 3 bureaus but with no balance until the 3rd.
Should I pay disco to 0 even though that means I'm all zero for over a week until the 3rd when Citi reports; or let disco report a balance and then let City report a balance until next months disco even though that means a bit less than a month with balances reported for both? Only alternative is just keep disco as the one reporting a balance but that will be harder to manage as Citi is the dd now.
@Bradac56Normal people don't do the above and just pay ccs when the statement is issued and have balances reported on all used cards. I dream of that convenience. This whole forum is the overthinkers club 
I did set up disco auto pay for minimum just in case life happens and I forget. I didn't do it for Citi yet because I'm micromanaging that one since it's used daily. Nothing to pay down, the stress comes in just trying to pay to zero, or specifically non zero but minimal util before reporting. Which is a massive pain.
@Kforcethat 7 year aaoc is a massive difference for "insufficient history" vs 1 though. I'm sure that's the whole difference right there, at least as far as prequal metrics... Hard to say with apps.
I'll have to explore Bill pay. I've honestly never used it because I've never trusted it with no control over when they pay vs pull that's reliable, or manual for regular bills. I know very little about how it works (like how do they know how much to pay, or do you preset a guesstimate? How reliable is posting, etc?). For the dd card it doesn't matter, I monitor it anyway. But for disco and other future cards it sounds very helpful for managing the zeros. I hate that the pulls don't let you pay before statement... But then as above normal people don't do that anyway....
I didn't even know you could move statement dates? Due dates I knew so least for some cards but not statement.
@uncredited, if you'd like, you can leave a small balance on the Discover card (provided you don't pay interest to do this), then pay it down after Citi reports. Once Citi reports, pay Discover to zero, then call in and ask them to report your zero balance. Discover and Chase are two banks that are known to report your current balance upon request.
When I was at all zero, my scores dropped between 4 and 45 points. Oddly, the weird Experian 04 (FICO 3) Bankcard score increased by four points.