Interest only under TCJA

[Sam Stout]

Hey!  Can anyone explain to me the new rules under the new tax plan about the limits of writing off mortgage interest, specifically on your primary residence?  I've hear it may be really beneficial to switch to an interest only loan for 10 years because then 100% of that payment will be able to be written off??   Below is what I am referring to.

Thanks!

"In addition, it may be beneficial to refinance your home using an interest-only mortgage. For example, if you refinance $1 million of pre-TCJA home acquisition debt with a new $1 million interest-only loan, you can continue to deduct all the interest under the grandfather rules. In contrast, if you gradually make principal payments on your $1 million of pre-TCJA home acquisition debt, you won’t be able to treat any portion of an additional home loan taken in 2018–2025 as home acquisition debt because your existing loan will absorb the entire $750,000 TCJA limit."

[Paul Allen]

My understanding is that home equity loans can also be deducted on the business schedule/return if used for business purposes. For example, interest on a home equity loan secured by the primary residence that is used to finance a rental property would be deductible on Schedule E as a business expense of the rental property.