If you’ve seen this listed as a reason your credit score isn’t higher, you’re looking at the age side of your credit profile. The scoring model is saying: your revolving accounts — credit cards, lines of credit — haven’t been open long enough to carry much weight. The fix sounds simple, but there are a few things worth understanding about how account age actually works before you act.
What “length of time revolving accounts have been established” actually measures
FICO considers two related age metrics: the age of your oldest account and the average age of all your accounts. Both show up in the “length of credit history” category, which makes up about 15% of your score. Revolving accounts (credit cards and lines of credit) carry more weight in this calculation than installment accounts for most buyers, because they involve ongoing credit management rather than a fixed repayment schedule.
When the model flags the length of time revolving accounts have been established as a negative reason, it’s saying your revolving accounts are too new, too few, or both. A profile with one credit card opened two years ago is going to score lower on this factor than a profile with two credit cards — one opened six years ago, one opened four years ago — even if all other factors are identical.
The math behind average account age
Here’s something that trips people up: every new account you open pulls your average age down. If you have one card opened six years ago and you open a new card today, your average age just dropped from six years to three years. That’s why the advice to “open more cards to build credit” is more complicated than it sounds — in the short term, new cards hurt the age metric before they help anything else.
This is also why people in thin-file situations can feel stuck. Their few accounts are relatively new, their average age is low, and the only way to organically raise that average is to wait. Time is the only natural fix for account age — you can’t speed up the calendar.
Except you kind of can, with authorized user tradelines.
How authorized user tradelines address account age
When you’re added as an authorized user on a credit card, that card’s full history — including its original open date — appears on your credit report. If the card has been open for eight years, your credit report now shows an eight-year-old account. The average age of your accounts goes up. The “length of time revolving accounts have been established” factor improves.
This is the primary reason people buy tradelines for age rather than for utilization. A $15,000 card with a nine-year history does more for the age factor than a $50,000 card opened two years ago.
Important exception: American Express. Since around 2015, Amex reports authorized users with the date they were added — not the card’s original open date. So that twelve-year-old Amex card? When you’re added as an AU, your report shows it opened today. The age benefit is completely gone. (I had a buyer come back after purchasing an Amex tradeline elsewhere expecting to see a decade-old account on their report. It showed up as a new account. The refund conversation wasn’t fun.) Chase, Capital One, US Bank, Barclays — those correctly transfer the original open date. Stick to those if account age is what you’re after.
What closing an old card does to this factor
Closed accounts in good standing stay on your report for up to ten years — so closing a card doesn’t immediately destroy your age metrics. But once that closed account eventually drops off, its contribution to your average age disappears. And you can’t use a closed card to keep your revolving utilization low. The general guidance is to keep older cards open even if you rarely use them, for this reason.
If you’re worried about an unused card getting closed for inactivity, a small recurring charge — a streaming subscription, a gas fill-up once a quarter — keeps it active without adding meaningful balance.
What tradelines can’t fix
Account age only matters as much as the rest of your profile allows. If you have derogatory marks — late payments, charge-offs, collections — improving your average account age will help your score, but the derogatory items will still weigh heavily and show up to manual underwriters. Tradelines add positive history; they don’t remove negative history. That requires FCRA disputes for inaccurate items or pay-for-delete negotiations with collectors.
The best use case for adding an aged tradeline is a thin file with no major negatives — someone building credit from scratch who wants to jump-start the age metric without waiting years for organic seasoning.
Yes — for most issuers, being added as an authorized user adds that card’s full history to your report, including its original open date. This can raise your average account age significantly if the card is older than your current accounts. The main exception is American Express, which reports AUs with the date added rather than the card’s original open date.
Generally no — closing an old card removes its future contribution to your average account age and kills the available credit limit (which affects utilization). Closed accounts stay on your report for up to ten years but eventually drop off. Keeping old cards open, even unused, is almost always the better move for this credit factor.
If account age is the factor you’re trying to improve before a specific credit application, here are the tradelines I have listed — direct from me with no broker markup. The tradelines FAQ explains what to look for when choosing a card for age versus utilization.
I also cover How to Hide your Credit Utilization in more detail in a separate post.
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