Under the scenario you describe, the loans would only be partially deductible.
First, you can only deduct up to the value of your home. So if, for example, the loans on your home total $300,000 and your home is only worth $280,000, that last $20,000 would not be deductible. For the rest of my answer, I will assume that the home equity line of credit, combined with all other mortgages tied to your primary residence, does not exceed the property's value.
An existing home owner who already has a mortgage, can take out additional mortgages for home improvement or repair. But if they take out a loan or line of credit for other purposes, such as financing other properties as in your case, then only the first $100,000 of additional borrowing would qualify as being tax deductible.
Since interest on debt on investment properties is already deductible as a business expense
, borrowing more than $100,000 would not make much sense from a tax perspective.
I hope this answers your question.
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