I don't have an answer for you but I hope someone else does. I just recently added my gf as AU for my 2 Chase cards (haven't received the cards yet). I'm curious to see how long it will be before they report.
There is no requirement that a creditor report AUs, particularly if the card holder is not a spouse.
Thus, the answer could vary between immediately ---> never.
I raised the issue of spouse only because the Equal Credit Opportunity Act (ECOA) explicitly permits a spouse to include certain aspects of joint holdings, such as income, in any credit application, and is often cited as legal basis for permitting AUs.
One spouse can, undr ECOA, include the income of the other without specific itemization as such when applying for credit.
That is extended by inference to AU accounts, but only when the other party is a spouse.
My Parents added me as an AU on their Chase card it showed on my Credit reprot less then 30 days and shot my score to the mid 600's
As Robert stated, sometimes AU accounts never show up. I would think if a few cycles go by and the account doesn't show up by then that chances are that it very well may never. Some creditors are very specific about if they'll report based on who the AU is, others don't seem to care.