5 OBBBA Tax Changes CPAs Must Know Before Filing 2025 Returns

Clients are calling with questions about the One Big Beautiful Bill Act - and if you're not ready with answers, you're behind. Five new deductions hit 2025 tax returns, and CPAs need to know how they work, what qualifies, and how to explain them without overselling the benefits.

Here's what you need to know before filing season picks up.

1. Tip Income Deduction

Clients heard "no tax on tips" and assumed tips are now tax-free. They're not. The deduction caps at $25,000 of qualified tip income annually, and it phases out once modified adjusted gross income (MAGI) exceeds $150,000 ($300,000 for joint filers).

Qualified tips means tips from food service, hospitality, and personal care industries. Cash tips, credit card tips, tip-sharing arrangements - all count if documented. Self-employed filers can claim it too, but the IRS just updated the rules last week, tightening eligibility and reducing the break for independent contractors.

2. Overtime Pay Deduction

Another "no tax" claim that's actually a deduction. Eligible workers can deduct up to $12,500 of qualified overtime ($25,000 for joint filers) from taxable income. Same MAGI phase-out thresholds as tips: $150,000 single, $300,000 joint.

The key word is "qualified." Not all overtime counts. The IRS defines it as hours worked beyond 40 per week at time-and-a-half or greater. Salaried exempt employees? Likely ineligible. Contractors? Depends on classification. Documentation matters - W2s don't automatically break out overtime for 2025, so clients need paystubs.

3. Senior Deduction

Taxpayers who turned 65 by December 31, 2025 get an additional $6,000 deduction ($12,000 for joint filers). This stacks on top of the standard deduction and the existing age 65+ deduction increase.

But it phases out once MAGI exceeds $75,000 ($150,000 joint filers). So high-income seniors don't get the full benefit - or any of it.

4. Vehicle Loan Interest Deduction

Up to $10,000 in interest paid on loans for new personal passenger vehicles is now deductible - if the vehicle's final assembly occurred in the United States and meets other IRS requirements.

Phase-out: MAGI over $100,000 ($200,000 joint filers). This one's narrow. Used cars don't qualify. Foreign-assembled vehicles don't qualify. Leases? Unclear. Expect questions.

5. SALT Cap Increase

The big one for high earners. The state and local tax deduction cap jumped from $10,000 to $40,000 for 2025. It phases out when MAGI exceeds $500,000, and both the cap and phase-out increase 1% annually through 2029.

This changes the itemize-vs-standard-deduction calculus for many taxpayers. If a married couple in a high-tax state was capped at $10K SALT and taking the standard deduction, they might now benefit from itemizing with the $40K cap.

What CPAs Need to Do

Clients don't understand these breaks. They heard "no tax on tips" and "no tax on overtime" and think it's a full exemption. It's not. Manage expectations early.

Documentation is messy. Employers weren't required to report taxable tips and overtime separately on 2025 W2s - that starts in 2026. So you'll need paystubs, tip logs, and employer statements. Build that into your intake process now.

IRS guidance is still evolving. The tips deduction changed last week. Expect more updates. Don't assume the first version of the rules is final.

And for high earners: the SALT cap increase is the real planning opportunity. Run the numbers. If itemizing makes sense now, revisit estimated tax payments and withholding strategy for the rest of the year.