I rarely put my spouse as an AU on my CC's & I do not have my spouse put me as an AU on hers. The one exception is I had her add me as an AU on two of her retail CC's opened in 1984/1985. That helped increase my average of accounts. Although I read that adding AU's does not increase FICO's due to past abuses, it helped my scores in my case. We have very deep, established credit histories since wife & I are in our 50's.

We mostly have CC's in just our names. I did put my wife on my Ink Bold to help with min spend on that card and biz cards do not affect FICO's. (the inquiry is on the credit report (CR )but the biz cards do not show up on personal CR.

Bottom line: We each apply for own own CC's. Why not? Each can have our own rewards!