When you apply for a loan, lenders check your credit report before accepting your application. The information in your report determines your credit score, and your credit score is key to determining your interest rate. So as long as a year before you apply, correct any errors and fix what you can.

Not all landlords or property management companies run credit checks—but many do. A lower score could reduce your likelihood of getting the apartment. Or the landlord may ask for a bigger security deposit if they think there’s a risk you won’t make rent.

If you have big expenses coming up, such as a home renovation, you may want your credit card issuer to raise your available credit to cover those costs. If your report shows missed payments or you have delinquent accounts, the lender may deny your request.

If you already have a car or house and plan to refinance your loan at a lower interest rate, your lender may check your credit to see whether anything in your financial situation has changed. High balances or inaccuracies in your credit report could give the lender reason to reject your refinance.

If you’ve gotten a collection call for someone else, received information in the mail about a credit card you didn’t open, or gotten a notice from the IRS that doesn’t seem to apply to you, those are all signs your credit may have been compromised. A look at your report can determine whether there’s fraudulent activity in your name.