Tax Planning for California Taxpayers

Most tax planning advice is written for a single tax system. California taxpayers operate under two, and the second one does not follow the first.

California’s conformity date is January 1, 2025 under Senate Bill 711 — signed in October 2025 but fixed at a date preceding the One Big Beautiful Bill Act. The result is that many of the strategies generating federal savings produce no California benefit at all, and a plan modeled on federal numbers alone will overstate the result, sometimes badly.

This page covers the planning areas where that gap matters most. We advise individuals and businesses in Temecula, Murrieta, San Diego, Riverside, and San Bernardino.

The Conformity Gap

Federal benefits with no California counterpart:

• Section 199A QBI deduction — up to 20% of pass-through income federally; nothing in California
• Bonus depreciation — 100% permanent federally; never adopted by California
• Section 179 — $2.5 million federally against California’s $25,000 with a $200,000 phaseout
• QSBS — Section 1202 exclusion up to $15 million federally; no California exclusion
• Tips and overtime deductions — temporary federal deductions for 2025–2028; fully taxable by California
• Opportunity zones — federal deferral only
• 529 K-12 withdrawals — tax-free federally, taxable in California with a 2.5% penalty on earnings

Every item produces a Schedule CA adjustment. Returns that carry federal figures across without the add-back create discrepancies the Franchise Tax Board detects and assesses.

The planning implication is not that these strategies are wrong. It is that their value must be computed on both returns — a federal 37% benefit and a California zero is a very different outcome from what a national calculator will show.

Where California Is Favorable

Two significant exceptions run the other way.

The pass-through entity elective tax. Extended through 2030 by Senate Bill 132, it lets a qualifying pass-through pay 9.3% at the entity level. That payment is deductible federally without regard to the SALT cap, and owners take a credit against California tax. For profitable S corporations and multi-member LLCs, this is usually the largest single planning item on the return. For 2026 and later, missing the June 15 prepayment no longer voids the election but reduces the credit by 12.5% of the shortfall.

Research expensing. California retains pre-TCJA Section 174, so both domestic and foreign research costs remain fully deductible for state purposes — more favorable than federal law, which amortizes foreign research over fifteen years. See the R&D credit.

No state estate tax is a third, though Proposition 19 property tax reassessment often costs California families more than an estate tax would. See estate tax planning.

Entity Structure

Entity choice is the highest-leverage planning decision for most business owners, and California’s entity-level charges change the analysis:

• LLCs pay $800 annually plus a gross receipts fee charged on revenue — up to $11,790 — regardless of profitability
• S corporations pay the greater of $800 or 1.5% of net income, and the 1.5% falls largely on the distribution slice the federal election is meant to shelter
• C corporations pay 8.84%, but only C corporation stock can qualify for QSBS
• Corporations are exempt from the minimum franchise tax in year one; LLCs no longer are

See entity formation for the full comparison.

Timing

Timing is the most reliable planning tool available, because it requires no unusual structure.

The SALT phasedown band. For 2026 the cap is $40,400, reduced by 30% of modified AGI above $505,000 but never below $10,000 — reaching the floor for joint filers near $606,333. Within that band, each additional dollar carries an unusually high effective marginal rate, because it simultaneously erodes the deduction. Accelerating income into that range is expensive, and deferring out of it is valuable.

Gain recognition. California taxes capital gains as ordinary income up to 13.3% with no preferential rate, so a large gain stacks federal tax, the 3.8% net investment income tax, and full California rates — approaching 37% combined. Installment treatment, loss harvesting, and spreading recognition across years all carry more weight here than in most states. See capital gains.

Retirement contributions reduce both federal and California income, making them one of the few strategies with no conformity gap.

Residency

Leaving California before a liquidity event is attempted constantly and examined accordingly — FTB residency audits of out-of-state filers rose 126% between 2019 and 2023.

Two independent questions decide these cases. Whether residency actually changed before recognition, judged by a closest-connections analysis under FTB Publication 1031 against a presumption of continued residency until domicile is affirmatively changed. And whether the income is California-source regardless of residency — gain on California real property and income attributable to a California business are taxed here either way.

Selling a business in the year of a move is the most reliably audited fact pattern in California tax practice. It can be done correctly, with planning and a documented record, and it cannot be done casually.

Compliance as Planning

The least glamorous planning is often the highest return:

• Reasonable compensation documentation for S corporation owners, prepared before an examination rather than during one
• Contemporaneous records for credits, vehicle and travel expenses, and home office claims — categories with strict substantiation requirements where estimates are not permitted
• Entity good standing, since a suspended entity cannot enforce its contracts or defend a lawsuit
• Reporting federal adjustments to the FTB within six months under R&TC 18622 — failing to report leaves the California assessment window open indefinitely

That last item is the most expensive omission on the list, and the least known.

Retirement Plans: Planning Without a Conformity Gap

Retirement contributions are unusual in this landscape because they reduce federal and California income alike. For a California business owner facing combined marginal rates well above 40%, that makes plan selection one of the more reliable planning levers available.

The options scale with the business. A SEP-IRA is simple to establish and allows employer contributions as a percentage of compensation, but requires proportional contributions for eligible employees. A solo 401(k) suits an owner with no employees other than a spouse and permits both employee deferral and employer contribution, producing a larger total at moderate income levels than a SEP would. A defined benefit or cash balance plan can accommodate substantially larger deductible contributions for an older owner with high, stable income and few employees — and carries actuarial cost and funding obligations that make it a commitment rather than an annual election.

Two interactions worth noting. Plan contributions reduce the qualified business income eligible for the federal Section 199A deduction, so the net federal benefit is smaller than the marginal rate suggests — though California, having no QBI deduction, has no such offset. And establishing a plan may qualify a small employer for the pension startup credit, which offsets part of the setup cost.

Deadlines vary by plan type and by whether the contribution is employee deferral or employer contribution. Some plans must be established before year end even though funding can follow, which makes this a fourth-quarter decision rather than a filing-season one.

Frequently Asked Questions

Does California follow the federal tax law?

Only through January 1, 2025. California does not conform to OBBBA, so bonus depreciation, expanded Section 179, QBI, QSBS, and the tips and overtime deductions have no California equivalent.

What is the biggest planning opportunity for a California business owner?

For most profitable pass-throughs, the PTE elective tax — a 9.3% entity-level payment deductible federally outside the SALT cap, with a credit against California tax. The June 15 prepayment deadline governs the credit amount.

Can I avoid California tax by moving?

Only for income that is not California-source, and only if residency genuinely changed before recognition. California-source income remains taxable regardless of where you live.

Why does my federal planning not reduce my California tax?

Because the strategies generating the federal savings — bonus depreciation, QBI, QSBS — were enacted after California’s conformity date and were not adopted by the state.

When should tax planning happen?

Before the transaction. Entity structure, gain timing, PTE elections, and residency all have deadlines that precede filing. By March, most of the year’s decisions are already fixed.

Is the SALT cap increase permanent?

No. The cap reverts to $10,000 in 2030, which makes the current window a planning period rather than a permanent condition.

What is the first thing to review?

Usually entity structure and the PTE election, because they affect every subsequent year and carry the largest dollar impact for most California business owners.

Plan Against Both Systems

The gap between federal and California treatment is where most planning value is either captured or lost. A strategy that works federally and produces nothing in California is not necessarily wrong — but it should be chosen knowing that, not discovered at filing.

Pietro Canestrelli holds an LL.M. in Taxation and advises individuals and businesses on entity structure, timing, gain planning, residency, and California-specific compliance. Schedule a consultation, or review our corporate tax and tax credits services.