If you’re dealing with restricted stock units (RSUs), you’re not alone—many families feel confident about their finances until tax time turns into a puzzle. RSU taxation can be surprisingly easy to misunderstand, and small reporting errors can lead to overpaying, underpaying, or getting an IRS notice. Here are some of the biggest RSU-related tax-return mistakes—and practical ways to avoid them.
1) Double-counting income from RSU vesting
The mistake: RSUs are typically taxed as ordinary income when they vest. Your employer often reports that income on your W-2. Later, when you sell shares, your brokerage 1099-B may not reflect the correct cost basis—leading some taxpayers to accidentally pay tax again.
How to avoid it: Confirm whether the vesting income is already included in Box 1 of your W-2. Then, when you report the sale, make sure the cost basis reflects the fair market value at vesting (plus any amount you paid, if applicable). Many people need to adjust basis on Form 8949 if the 1099-B basis is incomplete.
2) Assuming withholding means “taxes are covered”
The mistake: Employers often withhold a flat supplemental rate on RSU income. Depending on your total income, that withholding may be too low—which can create a surprise balance due (and potentially penalties).
How to avoid it: Treat RSU withholding as a starting point, not a guarantee. Consider running a quick tax projection or increasing withholding/estimated payments—especially in high-income years or if vesting is large.
3) Missing the timing: vest date vs. sale date
The mistake: Confusing the vesting date (taxable compensation) with the sale date (capital gain/loss) can cause incorrect reporting.
How to avoid it: Keep a simple RSU log: grant date, vest date, shares vested, price at vest, shares sold, sale date, and sale price. This helps you report ordinary income and capital gains in the right places.
4) Forgetting state and local tax complications
The mistake: If you moved states or work across state lines, RSU income may be allocated across multiple jurisdictions.
How to avoid it: Save your work-location history and grant/vesting details. Multi-state RSU taxation can be complex—this is a great moment to ask a tax professional about proper allocation.
5) Wash-sale surprises and concentrated stock risk
The mistake: Harvesting losses on company stock while also receiving new shares can accidentally trigger wash sales. Separately, holding too much employer stock can increase risk if your job and portfolio depend on the same company.
How to avoid it: Coordinate trading windows, vesting schedules, and any tax-loss harvesting strategy. Also consider a diversification plan that fits your goals and comfort level.
A helpful next step
RSUs sit at the intersection of benefits, taxes, and long-term planning. If you’d like, we can coordinate with your CPA to double-check basis reporting and build a strategy for withholding, selling, and diversification that supports your bigger picture.