Just one. All info is about John, except the DBA name, which goes in item 8.
And just to clarify things, if John Smith operates 6 businesses as sole proprietorships, each with a DBA name, but the CTR you are working on only involves one of those businesses, you do not involve the other 5 businesses in the CTR.
And, if your bank does not require sole proprietors to have a separate account for each of multiple DBA businesses, FinCEN does not require or suggest that you impose that requirement in order to separately break out reportable cash activity for each of the businesses.
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