My husband and I have a joint account, and I kept the personal account I've had for decades. We only included statements from the joint account, because my seoarate account seemed irrelevant. At his I-751/N-400 combo interview, the IO asked to see a statement from my account, because she saw, in our joint statements, some transfers I had made from one account to the other. We were not prepared for this. Fortunately for us, she was generous and gave me 15 minutes to get a statement to her, and my husband would be able to take the oath that afternoon. It was a stressful 15 minutes, but I was able to download and email the statement to her, and he did take the oath that day. My advice is to include everything you can, with a letter of explanation of how you run your finances - especially since it's already been an issue.