Closing a zero-balance credit card eventually hurts your credit age, but the damage is delayed. Closed accounts continue to report for up to 10 years from the date of closure (FICO and VantageScore both factor closed accounts during this period). After 10 years, the closed account ages off your report entirely, and your average account age can drop noticeably depending on what other accounts you have.

How credit age is calculated. Average age of accounts is the sum of every account's age divided by the number of accounts. Length of credit history factor in FICO is 15% of your score, comprising average account age and the age of your oldest account. A longer history is generally better. Older accounts and a higher average age improve the score.

The 10-year rule. Per FICO, closed accounts in good standing remain on credit reports for up to 10 years from the date of closure. During that 10-year window, the closed account counts toward your average account age. After 10 years, it ages off, and the average drops by however many months that account had been adding.

The example. Borrower has four cards: 15 years old, 8 years, 3 years, 1 year. Total accounts: 4. Average account age: (15+8+3+1)/4 = 6.75 years. Borrower closes the 15-year-old card after consolidation. For the next 10 years, the 15-year card still counts toward average age (which actually rises slightly each year as it ages). At year 10 from closure, the card ages off entirely. The remaining cards by then are 18 years, 13 years, and 11 years old. Average drops to (18+13+11)/3 = 14 years if no other changes, or substantially less if any of those got closed too.

Why this matters. The 10-year delay sounds like a long time, but borrowers who close their oldest cards systematically can find themselves with surprisingly thin file in their 40s and 50s. Someone who closed all old cards in their 30s ends up at 50 with 10-year-old cards as their oldest, instead of 30-year-old cards.

The mortgage timing trap. Even within the 10-year window, closed accounts can be treated differently than open accounts by some scoring models and underwriters. If you're applying for a mortgage in the next 24 months, closing zero-balance cards can have credit-score effects faster than the 10-year rule suggests.

How to keep them open without using them.

1. One small recurring charge. Set up the card to pay a $5 to $20 monthly subscription (Netflix, Spotify, gym, cloud storage). Set up auto-pay in full from your checking account. The card processes one charge a month and pays itself. No active management needed.

2. Auto-pay in full. Even cards with no recurring charge benefit from auto-pay being set up. If anything ever does post (a forgotten subscription you can't find, an annual fee you missed), it pays automatically.

3. Set a reminder to use it once a year. Some issuers close cards after 12 to 24 months of inactivity. A small annual purchase ($5-$10 at a coffee shop), paid off the next day, prevents inactivity closure.

4. Cut up the card or freeze it. If you don't trust yourself with available credit, physical removal works. Cut the card in half and throw it away (the account stays open and reports). Some borrowers freeze cards in a block of ice; the inconvenience prevents impulse use without closing the account.

What if the issuer closes the card for inactivity? The closure typically reports as "closed by grantor" rather than "closed by consumer." Most scoring models treat both the same, but the notation differs. Some issuers warn before closing (a notice that the card will be closed if not used within 30 days); others close without warning. Use cards at least once every 6 to 12 months to avoid this.

Cards with annual fees. If you have an old card with a $95 to $695 annual fee that you don't use, the math changes. Paying $95/year to keep the account open might be worth it for credit history; paying $695/year usually isn't. The middle ground: ask the issuer for a product change to a no-annual-fee card from the same issuer. Chase, American Express, Citi, and Capital One all offer this. The account history transfers; the new card has no fee. Best of both worlds.

What if you've already closed your oldest cards. Damage is done; can't reverse. Strategy: don't close any more for at least 5 years, focus on building positive payment history on what you have, and avoid the trap of closing in your 30s and 40s. By the time you're 50, your remaining open cards will be your oldest and the closed ones will have aged off.

Authorized user trick. Becoming an authorized user on a parent's or spouse's older credit card adds that card's history to your credit file. Some scoring models include the full history of authorized user accounts. This can substitute for closed-card history loss in some cases, though FICO 9 and 10 weight authorized user accounts less than primary accounts.

The decision tree. Card has no annual fee and you're not actively tempted to use it: keep it open. Card has an annual fee but you can product-change to a no-fee version: do that. Card is a high-fee card you don't use enough: consider closing, but only if no big credit needs are coming up in the next 24 months. Always keep the oldest 1-2 cards open if you possibly can.

Closing the cards is reversing the credit-score benefit consolidation just produced. Keep them open at $0 and let them work for you in the background.