My home mortgage is limited to the first $1M in loan. Can I expense home office portion separately over the $1M mortage limit?

[rkamath]

If I add up $1M personal portion of mortgage and home office portion of mortgage, then total is over $1M

[AmyC]

The total interest remains the same, you can break it up to allocate a portion of the allowed amount to your office.

Publication 587 (2020), Business Use of Your Home | IRS states: If you itemize your deductions on Schedule A (Form 1040), only include the personal part of your deductible mortgage interest on Schedule A (Form 1040), line 8a or 8b. The personal portion of your home mortgage interest will generally be the amount of deductible home mortgage interest you figured when treating all home mortgage interest as a personal expense and applying the Schedule A (Form 1040) limits on deducting home mortgage interest, reduced by the business or rental portions deducted or carried over as a business or rental expense on Schedule C, E, or F, or any form other than Schedule A. Home mortgage interest that exceeds the amount you figured after applying the Schedule A (Form 1040) limits on deducting home mortgage interest is not deductible as a personal expense.