Pub 936 p.12: Interest paid divided by interest rate method. You can use this method if at all times in 2023 the mortgage was secured by your qualified home and the interest was paid at least monthly.
However, it turns out you do have the option to omit the mortgage on the home you sold. See Pub 936 p.4: Choice to treat the debt as not secured by your home. You can choose to treat any debt secured by your qualified home as not secured by the home. This treatment begins with the tax year for which you make the choice and continues for all later tax years. You can revoke your choice only with the consent of the IRS.
You may want to treat a debt as not secured by your home if the interest on that debt is fully deductible (for example, as a business expense) whether or not it qualifies as home mortgage interest. This may allow you, if the limits in Part II apply, more of a deduction for interest on other debts that are deductible only as home mortgage interest.
