Become An Authorized User On My Credit Card

It usually takes around two months for the authorized user to show up on your credit profile.

Amex is rare in that it does not backdate credit history. This means regardless of primary card holder's age of Amex credit card account, the authorized user will not benefit from it. The AU of the Amex card will have the credit history start on the day they become an authorized user. 

If becoming an AU on Amex, don't do it for the credit history benefits, only the on time payments and increased credit line benfits. 

Yes. Depending on which card you signed up for, there will be an automatic charge to your credit card every two months. You can cancel this automatic charge at any time. 

Let me know you want to stop being an authorized user and I will take you off the account immediately. 

Yes, its important you are aware of what is entailed to become an authorized user.

Here is more information:

https://www.creditkarma.com/credit-cards/i/authorized-user-credit-card/

As long as you want.

According to Credit Karma, Transunion: 817 and Equifax: 810

No, you will not have access to the credit card or any part of the account. 

I will email you with once you make the purchase. After getting necessary information from you, I will immediately add you to the account as an authorized user. You can contact me with this email to remove you from the account.