A credit limit is the maximum outstanding balance an issuer allows on a revolving credit account — a credit card or personal line of credit. Spending above the limit typically triggers a fee or declined transaction; maintaining a low balance relative to your limit improves your [[credit-utilization]] ratio and credit score.
Credit limits are set by lenders based on your creditworthiness — primarily your credit score, income, existing debt obligations, and payment history. The CFPB's consumer credit guidance notes that issuers evaluate the same factors as a full credit application when extending a new limit or granting an increase. Your credit utilization ratio — the percentage of your available revolving credit currently in use — is calculated using your credit limit as the denominator. FICO scoring models weight utilization heavily; a ratio below 30% is generally considered favorable, and below 10% is optimal. This means a higher credit limit (with stable or lower spending) mechanically improves your utilization ratio and can raise your score. Issuers can lower your credit limit at any time, which can spike your utilization and lower your score even if your spending hasn't changed. When an issuer reduces your limit, they must notify you under the FCRA if it is based on information in your credit report.
Contact your issuer online or by phone. Issuers typically consider your income, payment history on the account, and how long you've had it. Some increases are automatic after consistent on-time payments; others require a formal request and may involve a [[hard-inquiry]].
The increase itself may cause a temporary small dip from a hard inquiry, but the improved utilization ratio usually produces a net positive effect over time — provided your spending doesn't increase proportionally.