About 15% of your FICO score is "length of credit history" — third-largest component after payment history (35%) and utilization (30%). It's a slow-moving lever, and the dominant strategy is one principle: keep your old accounts alive. The most common way people violate it isn't a deliberate decision. An old card sits unused, the bank closes it for inactivity, and a 10-year countdown starts on an account that used to be quietly anchoring your average age.
Credit age = 15% of FICO. Closed accounts stay on your report for 10 years, then drop off and pull your average age down. The cheapest defense: keep your oldest cards from being closed by the bank for inactivity. One small charge per quarter is enough.
Defend your oldest cards → or jump to pricingWhat FICO actually measures
"Credit age" sounds like a single number. FICO computes three sub-components:
1. Average age of all accounts
Mean age across every credit account on your report — open and closed (within the 10-year window). Add up the ages, divide by count. Three accounts opened 10, 5, and 1 year ago: average = 5.3 years.
2. Age of oldest account
The single oldest account. Older is better. This is what gives long-time cardholders an edge over newer ones.
3. Age of newest account
The most recent. Newer-than-X is mildly negative — it correlates with stressed profiles opening new credit.
Exact sub-weights aren't published, but average age and oldest age dominate. Newest age mainly flags "this person opened something recently."
The closed-account 10-year rule
Least-understood mechanic: closed accounts continue contributing to your average age for 10 years after closure. They're still on the report, still counted, just marked closed.
- Close a 12-year-old card today. It stays on your report for 10 more years, contributing 12+ years to your average each cycle.
- Year 10: the account drops off entirely. Your average recalculates without it.
- The drop's magnitude depends on how old the account was. A 22-year-old card falling off hits harder than a 5-year-old one.
Closure today doesn't immediately tank credit age. The damage is delayed by a decade — and at that point it can be material.
The dormancy trap
Most credit-age advice stops at "don't close your old accounts." Incomplete. The full advice: don't close them, AND don't let the bank close them for you.
The second half is more common. People rarely deliberately close their oldest cards. But they routinely stop using them because spending shifted to newer rewards cards. The old card sits unused. The bank's inactivity-review system flags it. The bank closes it.
From a credit-age perspective, that bank-driven closure is identical to a voluntary one. The 10-year clock starts. A decade later, your oldest account is gone and your average drops. This is why dormant cards aren't just a utilization problem — they're an age problem too.
What losing an old account actually costs
Immediately: the account stays on your report, so average age doesn't change. Score impact is from utilization — lost credit limit, typically 5–30 points.
Years 1–9: the closed account keeps aging alongside your open ones. No additional age-related damage.
Year 10: the account drops off. Your average recalculates. If the closed card was 25 years old at closure (would be 35 by year 10), removing it can pull your average down materially. Typically 10–30 points.
How to lengthen credit history
1. Keep your oldest accounts open and active
The foundation. Identify your oldest 1–3 cards. Make sure each has at least one posted transaction per quarter. Three reliable methods for keeping cards active.
2. Add an authorized user on a partner's old account
If your spouse has older cards than you, becoming AU transfers the account's age into your credit profile (in most FICO models). The only legitimate way to "borrow" credit age. Full mechanics.
3. Don't apply for new credit unnecessarily
Each new account drops your average. Average 8 years + new 0-year card = ~6–7 year average. The drop is temporary but real (10–20 points while it works through).
4. Prefer product changes over closures
A product change within the same issuer preserves the opening date. A new application starts a 0-year account. Always prefer the product change.
Protect your oldest card today
- Find your oldest open card.
- Check when you last used it.
- If it's been more than 90 days, make a small charge today.
- Set up either a recurring subscription with autopay, or onboard the card to an automated activity service.
- Repeat for your second-oldest.
The 10-minute investment of running this on your top 1–3 cards is the highest-ROI credit-age move available.
Why dormancy is the strongest argument for keeping old cards active
Credit age is the most patience-rewarded FICO factor: every year you keep accounts open, your average grows by one. The way to ruin it isn't bad behavior — it's letting old accounts close while you're not paying attention. An inactivity closure today is a delayed-action score event you won't feel for 10 years, and by then the fix takes another decade.
The prevention is cheap: one posted charge per quarter, on every old card you want to keep contributing. Manual works. Automation works better at scale. Doing nothing is the option that hands the bank your closure timeline.