Discover doubled my limit unexpectedly

[frugalfreedomplan163]

I applied for a credit line increase with Discover last month and was turned down. But when I logged in today, I saw that they had automatically bumped my limit from $2,500 to $5,000! I'm honestly shocked because my spending hasn't changed all that much. Has anyone else experienced these random automatic increases after getting declined?

 

[Billy Scott]

Do you think something in your credit report or account history might have improved since last month that could've made Discover change their mind and give you that automatic increase?