How can I raise my credit score fast?

Credit utilisation (the percentage of your total revolving credit you're using) is the second-largest factor in FICO scoring after payment history. It's also the factor that updates fastest because it's recomputed each month when your cards report.

For a card maxed at 95% utilisation, paying it down to 25% can produce a 30-60 point increase in the next reporting cycle. The strategy works on aggregate utilisation (across all cards) and on per-card utilisation; the most aggressive lift comes from improving both.

Disputing inaccurate negative items is the other fast lever. Pull all three credit reports at AnnualCreditReport.com (free). For each error (accounts not yours, accounts listed twice, incorrect balances, items past their 7-year removal date), file a dispute with the bureau. They have 30 days to investigate; the result usually appears in 14-21 days.