HELOC Tax Traps: When Is Your Home Equity Loan Interest Deductible?

Before 2018, the Home Equity Loan was a tax loophole. You could borrow against your house to buy a boat or pay off credit cards, and Uncle Sam would let you deduct the interest. Those days are gone. Under current tax law (TCJA), HELOC interest is only deductible if the money is used to “Buy, Build, or Substantially Improve” the home that secures the loan. If you use the money for anything else, the deduction vanishes. Here is how to navigate the strict “Tracing Rules” to avoid an audit nightmare.

BMT Tax Team BMT Tax Team · 📅 Feb 2026 · ⏱️ 6 min read · TAX › DEDUCTIONS
The Rule
B.B.I.
Buy, Build, ImproveFact
Debt Limit
$750k
Combined (1st + HELOC)Limit
Personal Use
0%
Deductible for Debt/CarsWarn
Visual comparison showing home improvement funds as deductible (left) and personal debt funds as non-deductible waste (right)

The Great Divide: Money spent on the home (Left) is deductible. Money spent on cars or credit card debt (Right) is trash to the IRS.

Image Source: bestmoneytip.com

1. The Golden Rule: “Buy, Build, or Improve”

The IRS is very specific. The money must be invested back into the property.

Expenditure Deductible? Why?
Kitchen Remodel YES “Substantial Improvement” adds value/life to property.
New Roof YES Extends the useful life of the home.
Debt Consolidation NO Personal expense. Does not improve the home.
Furniture NO It is personal property, not part of the structure.

2. The $750,000 Combined Limit

Remember the $750k cap from Article 504? It applies to your Total Mortgage Debt.

The Math Example
First Mortgage: $600,000 balance.
HELOC: $200,000 balance (used for a massive addition).
Total Debt: $800,000.
Deductible Amount: Interest on only $750,000.
Result: The interest on the last $50,000 is not deductible, even though it was used for home improvement.

3. The “Mixed-Use” Nightmare (Tracing Rules)

What if you take out a $50,000 HELOC and spend $30,000 on a pool and $20,000 on a car?

  • The Problem: The bank sends you one Form 1098 showing the total interest paid. They do not separate it for you.
  • The Solution: You must manually calculate the percentage.
    • $30k / $50k = 60% of the interest is deductible.
    • $20k / $50k = 40% is NOT deductible.
  • The Risk: If audited, you must show receipts proving exactly where the $30k went. If you can’t prove it, the IRS denies 100% of the deduction.

4. Is It Worth the Hassle?

Given the high Standard Deduction (see Article 504), does this even matter?

Probably Not If…
  • You have a small HELOC (e.g., $20k). The interest savings might only be $100/year.
  • You take the Standard Deduction anyway.
Definitely Yes If…
  • You already itemize deductions.
  • You have a large HELOC (e.g., $100k+) for a major renovation. The tax savings could be $1,000+.

5. Frequently Asked Questions

What about a second home?
Yes. You can deduct interest on a HELOC secured by a second home (vacation home), IF the money is used to buy, build, or improve that specific home. You cannot use a HELOC on Home A to fix up Home B.
I took the loan before 2018. Am I grandfathered in?
NO. The TCJA eliminated the deduction for all existing loans if the funds were not used for the home. There is no grandfather clause for “personal use” HELOC interest.