What's is DHH's credit score versus his wife? My wife and I file joint returns, she's a stay-at-home mom with no non-joint credit accounts, and has a different (higher!) credit score than me. I'm willing to wager that credit scores have a lot to do with this, especially credit score plus personal debt (I'm just assuming DHH's wife might still have some college loans?) plus percentage of credit utilization. There are a TON of factors that go into computing what one's credit limit should be but whether you're genetically an XX or an XY isn't part of it.