Tax Planning Mistakes That Create Avoidable Surprises

Default W-2 withholding assumes one job and no other income. Add a side business, a working spouse, RSUs, or rental income and the system underwithholds — sometimes by a lot. The fix is a mid-year projection, not the W-4 chart.

Without a mid-year check, all of Q4 planning becomes guesswork. A 30-minute projection in July tells you whether to fund more, withhold more, or pull deductions forward.

The savings from S-corp distributions are real, but reasonable compensation has to hold up. An aggressive salary becomes back payroll tax, penalties, and a re-characterization in audit.

Hiring a remote employee in another state, or selling into states above their economic nexus thresholds, creates filing obligations that owners typically discover only after a notice arrives. Map nexus once a year.

Section 199A's qualified business income deduction phases out by income, type of business, and W-2 wages paid. Big swings in compensation or income can quietly cost (or save) tens of thousands. It needs to be modeled, not assumed.

Maxing a Solo 401(k) at the wrong time, or Roth-converting in a high-income year because the rule of thumb said to, both leave money on the table. The decisions interact — model them together.

Every return should be compared line-by-line to the prior two years before filing. Unexpected jumps in tax liability almost always trace to a known cause — and if they don't, that's the moment to look for what's missing.