Generally speaking, any request for credit, be it for a new credit card or simply for an increase in the credit line on an existing card, will result in the lender pulling a copy of your credit report, thus creating an inquiry on your credit report. There might be times when the creditor, after a periodic review, might automatically increase your credit limit. However, the fact that an inquiry will appear should not prevent you from requesting credit, as long as you think you stand a reasonable chance of being approved. I would certainly recommend against repeatedly requesting additional credit on all of your credit cards, as multiple inquiries could have a strong negative impact on your credit rating. On the other hand, one or two inquiries may cause your credit score to decrease a small amount, but it should not cause any significant problem.
Let me briefly explain to you how credit inquiries work, as many consumers do not fully understand how the process operates and what problems inquiries may or may not cause on their credit reports. Whenever a company pulls a copy of your credit report, the credit bureaus will list an inquiry on your credit report. Credit inquires fall into two general categories: "hard" inquiries and "soft" inquiries. Hard inquiries, which can negatively impact your credit score, appear when a potential lender checks your credit as a result of your applying for new credit, such as applying for a new mortgage, car loan, credit card or asking for an increase in your credit line. Soft inquiries appear when a company pulls your credit without your prior authorization, or when you pull your own report. For example, when a credit card company runs your credit to send you an unsolicited "pre-approval" offer, the request will result in a soft inquiry. Soft inquiries are not disclosed to your potential lenders when they pull your credit report, and they do not affect your credit score.
If you would like to learn more about credit, credit reports, and credit scoring, I encourage you to visit the Bills.com Credit information page.
I hope that the information I have provided helps you Find. Learn. Save.