No, my wife is not an authorized user of any of my credit card accounts and I am not an authorized user of any of hers.
There is no reason for it other than help the charge card companies go after your spouse if something should happen to you.
Plus it would cost us money in cash back as we mostly get 5% back on everything we buy, but her cards have perks and my cards have perks and you use the cards in any given period of the most cash back.
Here is the perfect example. She has a Citi Card that gives 5% back during any month of the highest spending category. My cards right now do not give 5% back in restaurants. I get 5% on all gasoline, Walmart and groceries. I have a 2% Citicard which is the same all year and Amex with 3% in various categories all year.
So when we go out to eat during this 3 month period, since my cards have no 5% back on dinners we use her card exclusively for that and get 5% back on all restaurants. We tend to eat quality food (not fast food) so that 5% adds up too.
She also has other perks on other cards such as Amazon and I have other perks on others such as AMEX
None of these cards do we have authorized users on them.
Unrelated = We also buy $200 gift cards for Bonefish Grill and related companies for an additional 10% $200 cost $180 is another way to save money and then being a dine rewards customer we get bill credits on top of that and when buying the $200 gift cards we use online for $180 we also get another 2% back from my Citicard.