What is credit card churning?
Credit card churning involves opening new credit cards to get the intro bonus without intending to use the cards afterward. Churning isn't illegal, but it is controversial and frowned upon by card issuers.
Before credit card issuers really caught on and put systems in place to stop the practice, churners would open multiple credit cards in quick succession, earn the intro bonus for each new account and then close or stop using the cards. A few months later, churners would start again with another round of applications. While they had to meet the minimum spending requirements to earn the intro bonuses, there were tricks to accomplish that as well.
Credit card churning still happens, but many credit card issuers have updated the terms and conditions for their credit cards and rewards programs to stop it, or at least make it harder and less lucrative.
For example, the Chase Sapphire Preferred® Card and Chase Sapphire Reserve® both offer intro bonuses to new cardholders. However, you can only qualify for an intro bonus from one of the cards if you don't currently have either Sapphire card and haven't received a new cardmember bonus on either Sapphire card within the last 48 months.
Another example is Chase's unofficial 5/24 rule, which means the card issuer generally won't approve you for a new credit card if you've opened five cards within the last 24 months—including cards from other issuers.
Other card issuers may take similar approaches to stop people who may be trying to game their rewards programs. For example, American Express generally only allows you to earn the intro bonus on one of their cards once per lifetime. If you close your account, you can apply for the same card again in the future, but you might not be eligible for the intro bonus.
There have also been cases of card issuers taking back points that were earned by someone gaming the system. In a few cases, issuers have even shut down accounts, including checking and savings accounts someone has at the company