I've read that a closed account stays on your credit report for 10 years, and I've read mixed things that say for instance on FICO, a closed account will continue to age and impact
avg age of account (presumably to the point until 10 years after its closed and then it drops off your account)(ex, so an account thats closed at 6 months will continue to impact
avg age of account and there's nothing you can do, and then 10 years later that account will have an impact of 10.5 year, but will suddenly drop off).