Let's first try to simplify matters by designating Mr. Smith as the conductor of both transactions (because he's a payee on both checks and could complete the transactions himself if Mrs. Smith wasn't there).
And let's further assume that the joint payees on the checks still have an interest in those checks.
That leaves us with Mr. Smith as conductor of two cash-out transactions totaling $12,160. He did so on his own behalf and on behalf of the other two payees.
Part I, Mr. Smith, box 2a checked $12,160 in item 22. If either check is "on-us," its account number in in item 22
Part I, Mrs. Smith, box 2c checked, $160 in item 22. If $160 check is "on-us," account number from check in item 22
Part I, Mr. Jones, box 2c checked, $12,000 in item 22. If $12,000 check is "on-us," account number from check in item 22
Some might argue that the amounts in the Part I sections for Mrs. Smith and Mr. Jones should be half the respective check amounts. I don't agree because there is no way for the bank to know how much of each check "belongs" to those joint payees, and I don't see any scenario in which the conductor of the transaction would share that information with the bank.
And, of course, there is always the possibility that Mr. Smith is the only person that will get the full $12,160, if the joint payees on each check had negotiated their respective interests in the checks to Mr. Smith.
Let's also acknowledge that there is no guidance from FinCEN that addresses this scenario, so we are, in fact, making it up as we go along. And if a bank were to ask the FinCEN Help Desk for its take on this scenario, the response is likely to be "from the hip," too.
John S. Burnett
Fighting for Compliance since 1976
Bankers' Threads User #8