I have 2 CapOne credit cards, they show up as 1 account with both their credit limits combined on my credit report. My question is; Could I cancel one of those cards and apply for a better rewards card under CapOne without damaging my score? The CapOne account would still be active because I would have that other card still active.
Don't cancel a card then apply for a new one from the same place. Ask The bank if you can switch to a different card program. If you are a good customer they will do so willingly. It keeps your account as an active customer.
I have noticed that in the last few years the bank has been adamant that I should witch to a different program. When it is to my advantage I have done so. The only thing that changes is the words on the card, account number, expiration date and security code. There is no hit to my credit score. In fact with all the data breaches in the last few years every one of my card has undergone an account number change anyway.
It depends on how old the card is (i.e., when you opened the account) and the age of your average open credit accounts (credit accounts = loans, credit cards, etc). It will lower it if it's an older card, but if it's a newer card it will have a negligible effect, if any. In either case, the "ding" it may give you will go away in the short to mid term.
As others have said, it can also affect you if it accounts for a large percentage of your overall "available credit". Ask other cards for a credit increase, or open a new one if needed.
There will be a temporary (6 week) ding to your credit. Open the other one first.
the amount of available credit you have is 30% of your credit score. If there is no annual fee, keep it open and buy something twice a year that will help your credit score. If there is an annual fee and your credit score is over 550 get rid of it asap.