Anduril’s December RSU Settlement: What Employees Need to Know About Their 2026 Tax Bill

If you received Anduril RSUs in August, you may be facing another significant tax event before the year is over. Following the August 5, 2026, settlement and employee liquidity event, another RSU settlement is expected in December, although the exact date and terms have yet to be announced.

Meanwhile, Anduril has confirmed a new employee tender offer that values the company at roughly $90 billion, allowing eligible employees to sell shares at $94.80 each. With the offer closing November 9, participating employees could face additional capital gains taxes on top of the RSU income they’ve already recognized this year.

For employees who have already recognized substantial RSU income in 2026, December could add another layer of complexity to an already significant tax year. Understanding how the two settlements interact, where withholding gaps may arise, and what you can still do before December 31 could make a meaningful difference when tax season arrives.

Why might 22% withholding not cover your Anduril RSU tax bill?

When Anduril RSUs settle, the fair market value of the shares is generally treated as ordinary wage income. That income is added to your salary, bonuses, and other compensation for the year, even if you decide to keep the shares rather than sell them.

The problem is that the amount withheld for taxes may be considerably lower than your actual tax liability.

Under IRS supplemental wage rules, employers can generally withhold federal income tax at a flat 22% on qualifying supplemental wages up to $1 million. Once an employee’s supplemental wages from the employer exceed $1 million for the calendar year, the excess is generally subject to mandatory 37% federal withholding.

These are withholding rates, however, not necessarily the rates at which your income will ultimately be taxed. Your actual federal tax liability depends on your total taxable income, filing status, deductions, credits, and other tax payments.

What a withholding shortfall could look like

For an employee whose additional RSU income falls within the 37% federal marginal tax bracket, withholding at 22% could leave a 15-percentage-point gap.

These simplified examples assume the entire amount is taxed at 37% and is eligible for 22% withholding. Actual liability depends on your total taxable income, filing status, deductions, credits, and other tax payments. The mandatory 37% withholding rule for supplemental wages above $1 million is a separate consideration.

State income taxes and Medicare taxes can add to the overall obligation, particularly for Anduril employees living in California.

You can review the federal withholding requirements in IRS Publication 15.

The important takeaway is that having taxes withheld when your RSUs settle doesn’t necessarily mean your tax obligations have been fully covered.

How could Anduril’s December RSU settlement affect your 2026 taxes?

For employees who participated in Anduril’s August settlement, December could bring a second substantial increase in taxable income within just a few months. Even if the number of shares settling is similar, a change in the fair market value used for RSU taxation could produce a different tax outcome. This value isn’t necessarily the same as the $94.80 share price offered through November’s tender.

This is particularly important following Anduril’s transition to single-trigger RSUs, which allows eligible awards to settle without waiting for an IPO or acquisition. Employees who previously viewed their equity taxes as a future concern may now need to account for significant RSU income within their annual tax planning.

Two settlements, one tax year

The IRS doesn’t evaluate your August and December RSU income in isolation. Both contribute to your total annual income, alongside salary, bonuses, and other taxable compensation.

Consider an employee who recognized $300,000 in RSU income in August and expects another $200,000 in December. That’s $500,000 in additional wage income for 2026, before accounting for regular compensation.

The combined income could place more of the employee’s earnings in higher federal and state tax brackets. And if withholding was calculated separately for each settlement, the total amount withheld may not adequately reflect the employee’s year-end liability.

There’s also a timing consideration. With December approaching, employees have a relatively narrow window to review their projected tax position and make any necessary adjustments before the calendar year closes.

Rather than estimating the December tax bill on its own, consider how the expected settlement changes your full-year income, effective tax rate, and remaining tax obligations.

What if you participate in Anduril’s November tender offer?

Anduril’s newly confirmed tender offer gives eligible current and former employees an opportunity to sell shares at $94.80 each, reflecting a company valuation of approximately $90 billion. The offer opened October 13 and is scheduled to close November 9, with a reported maximum size of $1.3 billion.

Unlike RSU settlement income, which is generally taxed as ordinary wages, selling previously acquired shares typically generates a capital gain or loss based on the difference between the sale price and the employee’s tax basis.

For example, consider an employee selling 1,000 shares acquired during the August RSU settlement, when the fair market value was hypothetically $70 per share. That amount generally becomes the employee’s tax basis in the shares.

Because the shares were acquired in August, the $24,800 gain would generally be considered short-term and taxed at ordinary federal income tax rates, assuming the shares are sold within one year of acquisition. Different tax treatment may apply to shares acquired through stock options or held for longer periods.

The tender offer could provide cash to cover existing tax obligations or prepare for December’s expected settlement. However, employees who participate should also account for the additional taxes generated by the sale, particularly if they have already recognized substantial RSU income earlier in 2026.

How can Anduril employees estimate their December RSU tax bill?

You don’t need to know the final December share price to begin estimating your tax exposure. Working with a range of possible settlement values can help you understand how much additional income you might recognize and whether your current withholding is sufficient.

With Anduril’s November tender offer now underway, employees considering a share sale should also account for any potential capital gains or losses. The $94.80 tender price should not automatically be treated as the fair market value used to calculate taxable income from December RSUs.

Start by gathering your August settlement statement, most recent paystub, outstanding RSU details, and any records of estimated tax payments made during 2026. If you’re considering participating in the tender offer, review the tax basis and holding periods of the shares you may sell.

Four steps to estimate your potential tax liability

1. Calculate your expected RSU income.

   Multiply the number of shares expected to settle in December by an estimated fair market value per share. Consider several possible share prices rather than relying on a single valuation.

2. Add your other 2026 earnings.

   Include salary, bonuses, August RSU income, and any other taxable compensation to estimate your full-year income. If you participate in the November tender offer, calculate any resulting capital gains or losses separately and include their tax impact in your annual projection.

3. Estimate your federal and state taxes.

   Account for your filing status, applicable tax brackets, deductions, and other relevant income. You can use the Anduril RSU tax calculator to explore how different settlement values and withholding assumptions may affect your estimated liability.

4. Compare your projected taxes with payments already made.

   Review year-to-date withholding and estimated payments, then account for any additional withholding expected before December 31.

What if your calculations show a shortfall?

A projected tax gap doesn’t necessarily mean you need to sell shares immediately. Depending on your circumstances and the arrangements Anduril permits, you may have several ways to prepare.

These could include increasing withholding on remaining compensation, making an estimated tax payment, or setting aside cash to cover the difference when your return is due.

It’s also worth reviewing the IRS safe harbor rules for estimated taxes. Depending on your prior-year tax liability, current-year withholding, and adjusted gross income, you may be able to avoid an underpayment penalty even if you ultimately owe additional tax when filing.

The earlier you identify a potential shortfall, the more options you may have to address it without disrupting other financial priorities.

Example: Estimating your December RSU tax shortfall

Suppose an Anduril employee expects 2,000 RSUs to settle in December at a hypothetical fair market value of $150 per share. This figure is used solely to illustrate the calculation and is not a forecast of Anduril’s December share value or an estimate based on the $94.80 tender price.

In this simplified scenario, the employee could face a $39,000 difference between federal withholding and the estimated tax on their December RSU income alone.This is an illustrative difference on the December RSU income, not necessarily the employee’s final tax shortfall.

The calculation assumes the entire $300,000 is subject to a 35% marginal tax rate and qualifies for 22% withholding. Actual results depend on total annual income, supplemental wage withholding rules, and other tax factors. State taxes and Medicare taxes are excluded.

The example also shows why the December settlement shouldn’t be evaluated separately from August’s RSU income and the employee’s other 2026 earnings.

What should Anduril employees do before the December RSU settlement?

With only a few weeks remaining in the tax year, the decisions you make before December could influence how comfortably you manage the settlement and any resulting tax obligations. While the final settlement details remain unconfirmed, there’s plenty you can evaluate using the information already available.

Prepare for the tax bill without relying on a share sale

Anduril’s November tender offer may provide eligible employees with an opportunity to access cash before December, but it doesn’t eliminate the need to prepare for another RSU settlement. Participation limits, the timing of proceeds, and taxes on any realized gains could all affect how much money is available to cover future obligations.

Before the settlement, consider:

• Available cash: Do you have sufficient savings to cover a potential tax shortfall without drawing down your emergency reserves?
• November tender offer: If you’re eligible to participate, how much cash could you receive after taxes, and could those proceeds help cover your December obligations?
• Withholding arrangements: Will taxes be covered through withheld shares, payroll deductions, or another method permitted by Anduril?
• Estimated payments: Would an additional payment help address an anticipated shortfall or reduce potential underpayment penalties?
• Concentration risk: Would retaining the newly settled shares leave an even greater portion of your net worth tied to Anduril?
• Future settlements: Could additional RSU income create similar tax obligations in 2027?

For employees with substantial equity holdings, another settlement could increase the share of their wealth tied to Anduril. Understanding that exposure is particularly important when shares remain illiquid. You can use the Anduril Concentration Risk Analyzer to assess how your equity fits into your broader financial picture and how different valuation scenarios could affect your wealth.

Although the December settlement’s timing and terms remain unconfirmed, reviewing your tax exposure, available cash, and concentration risk now can help you prepare for the decisions ahead.

Get ahead of your Anduril RSU tax bill

December could bring another significant tax obligation, but you don’t have to wait for the final settlement details to understand your potential exposure. Augustus Wealth helps Anduril employees evaluate RSU taxes, prepare for withholding shortfalls, and make informed decisions about their equity compensation.

Connect with our team to develop a tax-aware financial strategy that accounts for both your immediate obligations and long-term goals.

Augustus Wealth, LLC is a registered investment adviser. Advisory services are only offered to clients or prospective clients where Augustus Wealth, LLC and its representatives are properly licensed or exempt from licensure. This content is for informational and educational purposes only and does not constitute personalized financial, tax, or investment advice. All examples are hypothetical and all figures are illustrative. Equity compensation strategies involve risks and should be evaluated in the context of your complete financial situation. Borrowing against securities involves risk, including the possibility of collateral calls. Tax laws change frequently. Consult your tax professional for advice specific to your situation. SpaceX, Anthropic, Anduril, and Databricks are referenced for educational purposes only. Augustus Wealth has no affiliation with SpaceX, Anthropic, Anduril, or Databricks. Calculator outputs are estimates and should not be relied upon as tax or financial advice. Past performance is not indicative of future results.