Length of credit history is roughly 15% of a FICO score. It is the factor most resistant to effort, which is why the practical advice about it is short and mostly about what not to do.
The three measurements
| Measure | What it looks at | How to protect it |
|---|---|---|
| Age of oldest account | Your longest-standing tradeline | Never close your first card |
| Age of newest account | Most recently opened tradeline | Space out applications |
| Average age of accounts | Mean across all open accounts | Open new accounts sparingly |
Opening a new card lowers your average age immediately. Someone with two accounts averaging ten years drops to about 6.7 years by opening a third. The effect is real, modest, and it recovers as the new account ages.
Closed accounts still count — for a while
A closed account in good standing generally remains on your credit report for around ten years and continues to contribute to your credit history length while it is there.
This is why the damage from closing a card is usually immediate through utilization and only distant through credit age. The utilization effect is the one to plan around.
A closed account with a delinquency history typically drops off around seven years from the delinquency, which in that case works in your favor.
Why starting early is worth so much
Two people, identical behavior, different starting points:
- Opened a first card at 18. At 28, they have ten years of history.
- Opened a first card at 25. At 28, they have three years.
The second person cannot catch up. They will have ten years of history at 35, by which point the first person has seventeen. This is the strongest argument for a secured or student card early, even one with unremarkable terms.
Authorized user status
Being added as an authorized user on an older account can, where the issuer reports authorized users, bring that account's history onto your report. It is one of the few ways to gain credit age you did not personally accumulate.
Two caveats. Not every issuer reports authorized users to all three bureaus. And because the arrangement is easy to create, some manual underwriters and newer scoring models discount authorized user tradelines. The benefit is real but not identical to history you built yourself.
What to do with this
- Open your first credit account as early as you responsibly can.
- Keep the oldest no-fee account open indefinitely, with a small recurring charge to prevent closure for inactivity.
- Space new applications several months apart.
- If a fee card no longer earns its keep, ask for a downgrade rather than closing — a product change usually preserves the opening date.
- Otherwise, ignore this factor. It is 15% of the score and largely outside your control.
