Account age refers to the average age of your credit accounts such as credit cards, student loans, mortgage, or car loans over the past 10 years. This figure provides lenders an indication of your experience with credit. For example an older account average with accounts in good standing suggests reliability to lenders. Keeping your older accounts open and in good standing improves your credit age over time.
Account age is considered a medium impact credit score factor as it's not as influential as your payment history or credit utilization, but a higher average account age still positively impacts your credit score.
Account age is a factor to take into consideration when closing or opening accounts. Closing your oldest account can reduce your average account age and negatively affect your credit score, especially if the account is in good standing. If you're not being charged an annual fee on your oldest account, it can be beneficial to leave this open. It can also be worth considering that opening new accounts will lower your average account age; although, that may also lower your credit utilization factor.
Ultimately, it's helpful to consider how opening and closing accounts will affect your average account age but it's also worth remembering that payment history and credit utilization have a greater impact on your credit score.