Let us take this simplified example:

Taxpayer had a mortgage with principal amount 650K through out 1/1/2022 to 12/31/2022 (assuming interest only payment), the interest amount is 30K. He bought a second home from 10/1/2022, and had a mortgage with principal 350K through the rest of year, the interest amount is 20K for the year.

In theory:

- Can you please write the formula to calculate the deductible mortgage interest for the year assuming 750K limitation?
- Assuming this person is in California, do you have a way to provide the federally not allowed portion to California?

In practice, how do you input the data in ProConnect software to get the correct answers for federal and California consistent with what you calculated in theory by hand?

PS: Please read my signature and vote for my idea. I cannot get an answer from support and they cannot open a case for me, if we push the idea to the top, it will get their attention. Thanks.