Key Takeaways:
- State conformity to the One Big Beautiful Bill Act will drive state tax complexity for private businesses.
- Understanding sales factor apportionment rules can uncover tax savings across jurisdictions.
- State transfer pricing strategies are essential to reduce audit exposure and double taxation.
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State and local tax (SALT) planning is entering a new phase of complexity. According to the BDO Tax Strategist Survey, over half of all audits and disputes stem from SALT issues. That’s no surprise — state rules evolve rapidly, vary across jurisdictions, and often conflict with federal tax changes.
The One Big Beautiful Bill Act’s (OBBBA’s) sweeping federal tax reforms will have significant ripple effects at the state level. Whether your business operates in a single state or across many, understanding state conformity and taking proactive steps around apportionment and transfer pricing will be essential to avoiding unnecessary tax burdens.
Why State Conformity Matters Now
The OBBBA introduces major federal tax changes that affect expense deductions, interest limitations, and depreciation. But these changes won’t automatically flow into state tax laws. States fall into two broad categories when it comes to conformity with the Internal Revenue Code:
- Rolling conformity states adopt new federal changes automatically unless they explicitly opt out.
- Fixed-date conformity states must actively update their laws to incorporate federal changes — and often tweak or reject certain provisions.
This means every federal tax strategy your business considers must also be evaluated through a state lens. For example:
- Section 174 expensing: Some states may continue to require five-year capitalization of research costs, while others move back to expensing.
- Section 163(j): The more favorable interest deduction rules under the OBBBA may not be accepted by revenue-conscious states.
- Bonus depreciation: Even with 100% federal bonus depreciation restored, many states already decouple and may ignore the new Section 168(n) provision for production-related building property.
- Section 250 deduction: State conformity will affect how foreign-derived deduction-eligible income (FDDEI) and net CFC tested income (NCTI) are treated — and differences in filing groups may require recomputation.
- Charitable deductions: The new 1% floor could create disparities between federal and state carryforward rules.
Planning Across State Lines with Apportionment
Once your business determines its state’s conformity profile, it’s equally important to revisit how income is apportioned. Nearly every state has revised its apportionment rules in the past decade — most moving toward single-sales factor formulas and market-based sourcing.
But that’s where consistency ends. Key differences include:
- States may source services based on where delivered, where the benefit is received, or where the customer lives.
- Some states use special rules for digital goods, IP licensing, or financial services.
- Rules for cascading sourcing methods and “reasonable approximations” vary widely.
Not applying the correct sourcing method in each state can lead to underreporting or overreporting income — resulting in missed savings or audit exposure. A thorough apportionment review can uncover errors and create opportunities for better outcomes. In some cases, businesses can even request an alternative apportionment method if the standard approach unfairly reflects activity in each state.
When federal rules shift, your state tax picture shifts even faster. Companies that plan early avoid costly surprises.
Don’t Overlook State Transfer Pricing
While federal and international transfer pricing often receive the most attention, state-level transfer pricing can be just as impactful. Nearly half of all states apply their own standards — many diverging significantly from IRS guidance. If your business engages in related-party transactions, you must consider:
- Separate versus combined reporting states
- Disallowance of intercompany expense deductions
- Lack of safe harbors or advance pricing agreement (APA) recognition
Failing to tailor transfer pricing documentation and analysis to state requirements can result in double taxation, audit adjustments, or denied deductions. The risk is especially high in states that require separate filing, where intercompany pricing has a more direct impact on the tax base.
By embedding state-level transfer pricing into your broader planning and documentation processes, you can align pricing with each state’s rules and reduce both tax and risk.
State tax is no longer a compliance exercise. It is a strategic risk — and opportunity — that businesses must manage proactively.
What Businesses Should Do Now
To avoid being caught off guard by the evolving SALT landscape, your business should:
- Review conformity status in each state where you file and assess how OBBBA changes will be applied
- Perform apportionment studies to support compliance and uncover savings
- Reassess transfer pricing positions with state-level exposure in mind
- Evaluate restructuring or M&A plans for state tax impact before execution
- Enhance audit readiness by keeping strong documentation and working with professionals who understand state-specific rules
State taxes are no longer a back-office issue. They affect business structure, pricing strategies, and profitability. And in a high-scrutiny environment, businesses that ignore SALT do so at their own peril.
How MGO Helps You Navigate State Tax Complexity
State and local tax rules are constantly shifting — and we will help you stay ahead. MGO’s SALT professionals guide private businesses through the complexity of state conformity, apportionment, and transfer pricing.
We map how federal changes affect your state’s obligations, design apportionment strategies aligned with your revenue, and enhance your intercompany pricing holds up across jurisdictions. When audits arise, we back you with clear documentation and skilled advocacy.
Whether you’re expanding, restructuring, or responding to new legislation, MGO helps you move from compliance to confident, strategic tax planning. Contact us today to see how we can simplify state tax planning for your business.