The old way is still the right way when one joint owner completes a reportable deposit to a joint account. One Part 1 for the conductor with 2a checked, and one Part 1 for each of the other joint owners with 2c checked.
But what if H deposits $5,000 and W deposits $7,000 (both in cash) to their joint account?
In that case, you do four part 1 entries:
- H 2a with $5,000 in item 21
- W 2c with $5,000 in item 21
- W 2a with $7,000 in item 21
- H 2c with $7,000 in item 21
and $12,000 in item 25
See Question 23 in FinCEN's CTR FAQs HERE
. The answer to your original question is in the "note" at the end of the answer.