Definition: Your available credit is the amount of credit you are able to use for purchases. Your available credit is usually your credit limit minus your balance, but it could be lower if you have pending transactions that haven't posted to your credit card yet.
Having available credit is good for your credit score because it means you're keeping your credit card balance low. Consequently, your credit utilization, which is 30% of your credit score, will also be low. It's a good idea to keep your credit card balance below 30% of your credit limit. That means you'll have a balance of $300 and $700 available credit on a credit card with a limit of $1,000.
If you try to spend more than your available credit, your transaction will be declined, unless you've opted-in to have over-the-limit transactions processed. In that case, using more than your available credit will result in an over-the-limit fee.
