I have a store credit card with a $1,500 limit that I've had for about six years, which I use occasionally to earn store points. They recently changed their program and switched to an actual MasterCard, and sent me a new card with an $11,000 limit. I did not ask for the new card and I certainly don't need it. How will this affect my credit and is it better to keep it or should I send it back as refused?
See my answer when you read more.
Definitely ask questions before using the card, but don't cancel it. The huge jump in your credit limit could actually help your credit score if you are carrying balances on any of your cards, because it effectively lowers your credit-to-debt ratio. I advise against canceling the card because you've had it for a long time and getting rid of it would hurt your credit score. As long as you're not tempted to rack up charges on the credit card — and it sounds like you've always been responsible with it — the limit isn't hurting you.
Store cards are run on platforms owned by various banks or carriers, and when the store switched to MasterCard it probably reviewed the customer base and saw that you are a regular customer with a low credit limit. Your credit score must be very good for the store to extend additional credit to you at a time when some are cutting limits or canceling cards altogether.
Before you go shopping with the card, call the carrier to be sure of the terms, penalties, and interest rates. If you keep using the card responsibly and paying it off immediately, your credit score shouldn't be negatively affected by carrying a card with a higher limit.