From my experience doing AZEO the last 2 years, you need 1 of your accounts you're the primary card holder on to report a balance to avoid the zero balance penalty. The person's cards who you are an AU on, in this case your wife's, reporting $0 balance won't affect your scores, regarding any $0 balance penalty. It'll only affect theirs if they have no other cards reporting balances. They can also practice AZEO if they want to get the same score bonuses you're getting.
This is super helpful, thank you! So as long as we keep the utilization low on the AU account (we have one at zero and the other we carry at around 100/6000 like I mentioned), then I will carry one of mine around $10 and the others at zero.
Appreciate the reply 
@Anonymous wrote:Hello all,
I have been reading through countless AZEO threads and I came across a few places with some contradicting information. I am trying to maximize for a mortgage score currently.
- I have 8 cards currently
- Two are AU cards
- 6 are individual
- All are bank cards
I read somewhere that AU counts and somewhere else where it said that I didn't. Currently, my wife and I are using one of the joint accounts where I am an AU to carry a low balance (<100/6000). I have paid everything else to zero but they haven't updated.
- Should I expect an all zero penalty when all of my individual accounts hit zero?
- And if so, should I pay hers down to zero so that only mine has a balance? Or do I need both an AU and an individual account with a balance?
I guess I am trying to verify how the AU accounts count overall. Thank you so much in advance!!
This may sound crazy but there are 2 separate AZEO metrics, 1 for your accounts and 1 for your AU cards. To optimize you need to be in compliance with both. So on your 6 cards, 1 should report a balance. And on your 2 AU cards, 1should report a balance.
I must confess that when I first heard people speculating on the existence of a separate AZEO algorithm for AU cards I was skeptical. But then I actually tested it with a family member a few times, and verified that it is real.
@Curious_George2 wrote:My experience is the opposite. I get one penalty for having no reported balances on my individual cards, and a second penalty if I am an AU on some cards and all of them report zero balance.
There are a fair number of threads here that discuss the AU AZ penalty.
One thing that can cause a lot of confusion is that, starting with Score 8, FICO includes an anti-abuse algorithm that excludes some AU accounts from affecting the score at all. Its inner workings are mysterious, so most people will never know if their AU accounts are scored. But that feature does not exist in the older scoring models that are used for mortgage scores. They count all AU accounts in scoring.
TL;DR - There is some evidence that the mortgage scores have two different all-zero penalties; one for individual accounts, the other for AU accounts.
You are 100% right about this @Curious_George2 As odd as it seems, it is true.
@Anonymous wrote:This is super helpful, thank you! So as long as we keep the utilization low on the AU account (we have one at zero and the other we carry at around 100/6000 like I mentioned), then I will carry one of mine around $10 and the others at zero.
Appreciate the reply
@Anonymous You're welcome! Also yes, as long as you're keeping the utilization low on the AU's cards and your cards you're gonna reap all the benefits of AZEO. I keep mine between $5 and $20 so $10 is fine. Best wishes to y'all when you apply for the new mortgage!
@Anonymous wrote:Truly appreciate everyone's replies as this gives me a lot of clarity. Here is where I will be after this next reporting cycle:
AU accounts:
- $0
- $97/6000
Individual accounts:
- $0
- $0
- $0
- $11/475
- $0
- $0
This should be good, right? It gives me AZEO both in my individual bucket and my AU bucket and also keeps my aggregate utilization low enough.
Perfect.