Part 4: What is the Difference between an Authorized Card User and an Joint Account Holder?

• Part 1: Why Apply? Myths about Credit Card Sign-up Bonus Offerings
• Part 2: How to fix my credit score (FICO)?
• Part 3: What are the best credit cards for Beginners interested in travel-reward credit cards?
• Part 5: Are Credit Card Bonus Miles and Points Taxable? Mostly No, says Chase, Citi, AMEX

What are the Pros and Cons for adding an authorized card user versus joint account card holder?  I asked this question when I was considering various methods to lift my wife's credit score.  I had to make some changes in my plan because of the rules of credit card sign-up bonus program.  There are constantly confusion among credit card applicants, including myself.  My readings on other people's testimony and my own experiments indicate that:

Authorized User
Assume Barney is the primary credit card holder, and Wilma is the second card holder.

• Wilma does not lose eligibility to receive sign-up bonus when applying the same credit card on his own.  For example, after Barney receives 40000 bonus points from Chase Sapphire Preferred card, Wilma will receive separate 40000 bonus points when she applies for her own card.
• Piggybanking credit strategy most likely would not work here.  If Barney has excellent credit score, it does not lift up Wilma's. 
• Wilma is able to use the card and NOT RESPONSIBLE for the card balance.

Joint Account Holder

• The joint credit card user may lose eligibility to receive sign-up bonus when applying the same credit card on her own.
• Piggybanking credit may be applicable. If Barney has excellent credit score, it may lift up Wilma's.
• Wilma is able to use the card and also RESPONSIBLE for the card balance.

Which option is preferred would depend on the objective of the primary card holder.  During credit card application process, the primary card applicant would have the opportunity to indicate whether interested to add an additional card user.  The application form may refer that as an "authorized" user, when it is indeed joint account holder card.  Regardless, I follow my safe approach that if the form asks for social security number, then it actually refers to adding a joint account holder, such as in American Express Hilton card online application.

If the form does not ask for social security number but simply additional card user name, then it refers to an authorized user, such as in Citi Hilton Visa card online application. An Credit card issuer is required to possess social security number to dig into the additional user's credit history. 

Because of these differences, to avoid losing eligibility of those incredible Chase credit card sign-up bonuses such as Chase Sapphire Preferred 40000, Chase United Airline 50000 and Chase Marriott 50000, my wife and I have separate Chase checking accounts and online accounts.  We still file Federal Tax Return as joint married couple.

What is the reason to add an additional authorized card user then?

• To help meeting the minimum spending requirements.  Of course, the person must be trust-able.
• Sometimes, adding an authorized card user may receive extra bonus points.