When and how to ask for a limit increase
A higher limit is one of the cleanest ways to lower utilization, but only if you ask the right way at the right time. CardClx has a per-card tracker for exactly this.
Why ask
A higher limit, with the same spending, lowers your utilization, which can help your score. It also gives you more room for a large purchase you will pay off.
Soft pull versus hard pull
Some issuers do a soft pull for an increase request (no score impact) and some do a hard pull (a small, temporary ding). Always check which before you ask, and avoid hard-pull requests in the months before a mortgage, auto loan, or other major application.
Timing
Wait until your account has some age and a record of on-time payments, then ask periodically rather than constantly. The tracker in CardClx estimates a sensible next-ask date per card from issuer cadence and the dates you enter. These are community-collected data points, not bank-published rules.