While using up to 100% of your credit card limit is possible, it's generally not recommended. There are a few reasons for this:
High credit utilization can negatively impact your credit score: One factor that goes into calculating your credit score is your credit utilization, or the amount of credit you're using compared to your credit limit. Using too much of your credit limit can indicate to lenders that you may be a higher-risk borrower, and your credit score may suffer.