Here are the basics:
The 5/24 rule is specific to Chase Bank.
5= 5 personal credit cards from any bank
24= opened in the last 24 months
So... if you've opened 5 or more personal cards in the last 24 months, you'll be declined for any new Chase cards- personal or business.
Why does this matter?
Chase has some really valuable cards- especially the Ink Business cards that have low annual fees, unique transfer partners, and make it easy to rack up a ton of points quickly! If you aren't careful with your 5/24, you may cut yourself out of hundreds of thousands of points.
The 5/24 Rule also applies to co-branded cards (Southwest, Hyatt, Marriott, United). If you want to earn the Southwest Companion Pass via credit cards, you'll need to be under 5/24 to be approved.
What counts toward 5/24?
All personal cards from any bank opened in the last 24 months (and a couple of business cards) will count toward your 5/24. Also, being an authorized user also shows up on your credit report and could hurt your 5/24 status. If you are under 5/24 on your own cards, but being an authorized user is the reason you are declined, it is worth a call to the reconsideration line-- we have found that Chase will sometimes overlook these AU cards and approve you.
The great news is, most business cards do not count toward 5/24.
Tips:
-Use an app like Travel Freely to track your (and your Player 2's) 5/24 status
-Avoid adding your Player 2 as an authorized user
-Major on business cards (they often have more valuable sign-up bonuses anyway)