Estate Tax Planning for High Net Worth Individuals: Why Portability and Proper Administration Matter

Top 3 Key Takeaways

1. Portability Is Not Automatic — It Requires Filing Form 706

Even if no estate tax is due at the first spouse’s death, the estate must file a federal estate tax return (Form 706) to elect portability and preserve the deceased spouse’s unused exemption. Failing to file means permanently losing that exemption — potentially exposing millions to a 40% federal estate tax at the second death.

2. Filing Is Not Enough — It Must Be Done Correctly

High net worth estates often include closely held businesses, real estate, and illiquid investments that require qualified appraisals. Using estimated or unsupported asset values can invalidate a portability election. Technical compliance and defensible valuations are critical.

3. Estate Planning Fails in Administration, Not Drafting

Most estate tax problems for HNW families arise after death — through missed deadlines, improper trust funding, or incomplete filings. Sophisticated estate plans only work if post-death administration is handled with the same precision as the planning itself.

Definition: HNW – High Net Worth

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High net worth individuals spend significant time structuring trusts, minimizing estate tax exposure, and designing wealth transfer strategies. Yet one of the most common estate tax planning failures does not happen in drafting — it happens after the first spouse dies.

For HNW families, estate planning is only as effective as the post-death administration that follows. A missed portability election or improperly prepared Form 706 can result in millions of dollars in unnecessary federal estate tax.

If you don’t have time to read, you can watch Noelle Minto discuss the issues here in this video:

The Critical Step Many Families Miss: Portability Election

Under current federal estate tax law, each individual has a lifetime estate tax exemption. For married couples, preserving both spouses’ exemptions is often essential to minimizing estate tax at the second death.

To preserve the deceased spouse’s unused exemption, the estate must file a federal estate tax return (Form 706) and affirmatively elect portability.

This filing requirement applies even if:

• No estate tax is due at the first death
• All assets pass to the surviving spouse
• The estate is below the exemption amount

No filing means no portability. No portability means the second exemption is permanently lost.

For high net worth individuals with estates that may exceed one spouse’s exemption — particularly those holding appreciating business interests, private equity, concentrated stock, or real estate — this administrative step is critical.

Federal Estate Tax: The 40% Exposure

The federal estate tax rate is 40% on amounts exceeding the available exemption. The tax is generally due within nine months of death.

For a $30–40 million estate that fails to preserve the first spouse’s exemption, the avoidable tax liability can reach several million dollars.

This is not aggressive tax planning. This is baseline estate tax compliance.

A Real-World Estate Tax Mistake

In the 2025 Tax Court case Roland v. Commissioner, the surviving spouse attempted to elect portability by filing Form 706. However, the return relied on estimated asset values rather than properly supported qualified appraisals.

When the surviving spouse later died, the IRS challenged the validity of the portability election due to valuation deficiencies.

The result: the deceased spouse’s unused estate tax exemption was not preserved.

The lesson for high net worth families is clear: filing Form 706 is not enough. It must be filed correctly, with defensible asset valuations.

Why Proper Valuation Is Essential for HNW Estates

High net worth estates often include:

• Closely held businesses
• Investment partnerships
• Commercial real estate
• Illiquid private investments
• Significant brokerage accounts

For estate tax purposes, the IRS requires that certain assets be supported by a qualified appraisal performed by a qualified appraiser. Informal estimates, broker opinions, or internal calculations are not sufficient.

Improper valuation can jeopardize portability elections and other estate tax positions. For complex estates, valuation compliance should be treated with the same rigor as transaction-level due diligence.

Trust Administration Mistakes That Trigger Estate Tax Problems

Common post-death administration errors among high net worth individuals include:

• Failing to file Form 706 when no tax is due
• Missing portability election deadlines
• Using estimated values instead of qualified appraisals
• Failing to fund subtrusts properly
• Not retitling assets according to trust terms

These are not minor clerical oversights. They are fiduciary responsibilities with substantial tax consequences.

The “We’re Below the Threshold” Assumption

Many affluent families assume estate tax is not an immediate concern because their current net worth falls below the exemption amount.

However:

• Asset appreciation can rapidly increase estate size
• Business liquidity events can change exposure overnight
• Federal exemption levels are subject to legislative change

Electing portability preserves flexibility and protects against future growth or tax law shifts.

Estate Tax Planning Does Not End at Death

For high net worth individuals, estate tax planning is not complete when documents are signed. The first spouse’s death triggers a technical legal and tax process that must be handled with precision.

Properly filing Form 706, electing portability, and obtaining qualified appraisals are foundational steps in preserving generational wealth.

For families focused on long-term legacy, disciplined trust administration is not optional — it is essential.

Frequently Asked Questions