Authorized user and length of credit

[Zippy9]

This is in general and not specific to any one model, but I know adding an authorized user can help that user build their credit. Does that mean that if you add the user that it will also affect their average length of credit? Meaning if it's a brand new card you add them to, it could initially lower their average length and negatively impact their credit initially?

Or does average length of credit only account for things they are primary on?

[Anonymous]

yes it affects length just like any other account

[Zippy9]

Thank you!

what if it is an existing account, say one that has been open 5 years. Would it show as 1 month when added or 5 years?

[Anonymous]

Adding an AU causes that account (of the primary cardholder) to report to the AU's credit report.  Once that account lands on their report, their age of accounts are impacted by that account.

Generally speaking, those that look to be added as an AU for scoring gain purposes are looking to be added to an account that is [significantly] older than their average age of accounts.  If someone with a low average age of accounts were to be added as an AU to an account with an even lower age than their average, it would adversely impact their average age of accounts and therefore not accomplish the general goal of the AU addition for score gain purposes.

[AllZero]

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@Zippy9 wrote:

This is in general and not specific to any one model, but I know adding an authorized user can help that user build their credit. Does that mean that if you add the user that it will also affect their average length of credit? Meaning if it's a brand new card you add them to, it could initially lower their average length and negatively impact their credit initially?

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Correct. In general, the account age carries over, new or aged. Unless it is an American Express card, then the age starts as the date of user being added as AU Authorized User, which in essence is adding a new card.

Note, anti abuse alogrithm may be in effect in FICO 8/9. See message 3. C. All Zero Point Loss- (AU Test included)

I would recommend reading the below from Birdman7
General Scoring Primer and Version 8 Master Thread, pub.5.17.20

[Anonymous]

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@Zippy9 wrote:

Thank you!

what if it is an existing account, say one that has been open 5 years. Would it show as 1 month when added or 5 years?

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Under the majority of circumstances, 5 years. 

If it were 1 month, people wouldn't look to be added as AU's for age of accounts / scoring-related benefits related to it.

[Avinor]

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@AllZero wrote:

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@Zippy9 wrote:

This is in general and not specific to any one model, but I know adding an authorized user can help that user build their credit. Does that mean that if you add the user that it will also affect their average length of credit? Meaning if it's a brand new card you add them to, it could initially lower their average length and negatively impact their credit initially?

---

Correct. In general, the account age carries over, new or aged. Unless it is an American Express card, then the age starts as the date of user being added as AU Authorized User, which in essence is adding a new card.

Note, anti abuse alogrithm may be in effect in FICO 8/9. See message 3. C. All Zero Point Loss- (AU Test included)

I would recommend reading the below from Birdman7
General Scoring Primer and Version 8 Master Thread, pub.5.17.20

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I know this is 3 months old, but your statement peaked my interest.

My wife just recently got her SSN so I wanted to help her build credit as one of the first activities.
Instead of adding her to all my cards I just added her to my oldest Amex (about 2 years of age) and then found out that on her credit report the start date of the card was the date I added her. Regardless she managed to now get her own Amex card without the need of another secured etc. but I was considering to dispute the Amex listing.

Based on your comment the answer seems to be no, Amex reports differently than other issuers?

[calyx]

Amex is one of the FIs known for not reporting history with a card - bad luck on that one.