2025 Year-End Tax Write-Offs for LLCs: New Bonus Depreciation & SALT Rules

As we approach the end of 2025, limited liability company (LLC) owners are navigating a significantly altered tax landscape. The passage of the One Big Beautiful Bill (OBBB) Act, signed into law on July 4, 2025, has introduced sweeping changes to the Internal Revenue Code, specifically targeting capital expensing and state and local tax (SALT) deductions. For small business owners, these changes offer powerful opportunities to reduce taxable income before the fiscal year closes.

This guide provides a comprehensive overview of LLC Tax Write-Offs 2025, focusing on the reinstatement of 100% bonus depreciation, the expanded SALT deduction caps, and the strategic use of Section 179. All advice herein is based on the legislative updates effective for the 2025 tax year.

Key Takeaways for 2025 Tax Planning

• 100% Bonus Depreciation Returns: For qualified property acquired and placed in service after January 19, 2025, full expensing is permanently reinstated. Assets placed in service on or before this date are generally limited to 40% bonus depreciation.
• SALT Deduction Cap Quadrupled: The State and Local Tax (SALT) deduction cap has increased to $40,000 for married couples filing jointly (up from $10,000), subject to income-based phaseouts starting at $500,000.
• Section 179 Limits Boosted: The maximum deduction for 2025 is now $1,250,000, with a phaseout threshold beginning at $3,130,000.
• Standard Deduction Adjustments: The standard deduction for 2025 stands at $15,750 for single filers and $31,500 for joint filers, influencing the choice between itemizing and taking the standard deduction.
• New Tax Brackets: The top marginal rate remains 37%, but it now applies to taxable income above $626,350 for single filers and $751,600 for joint filers.

Detailed Breakdown: 2025 Bonus Depreciation Rules

The most significant change for 2025 Bonus Depreciation is the bifurcation of the tax year based on the acquisition date. The OBBB Act has effectively split the year into two distinct periods for asset expensing, requiring LLC owners to meticulously track when an asset was acquired and placed in service.

The January 19, 2025 Cutoff

Under the new legislation, the percentage of bonus depreciation you can claim depends strictly on the date the property was placed in service:

• On or Before January 19, 2025: Assets placed in service during this window are generally eligible for only 40% bonus depreciation. This is a carryover from the phase-down schedule of previous legislation.
• After January 19, 2025: Assets acquired and placed in service after this date are eligible for 100% bonus depreciation. This provision is now permanent under the OBBB Act.

Note on Transitional Election: There is a transitional election available that permits taxpayers to apply the lower 40% rate to property placed in service after January 19, 2025. This may be strategic for businesses with lower income in 2025 who wish to save deductions for future years where they might face higher tax brackets.

Qualified Property

To qualify for these write-offs, the property must be “qualified property” under the IRS definition. For 2025, this includes:

• Tangible business assets with a recovery period of 20 years or less (machinery, equipment, office furniture).
• Computer software.
• Water utility property.
• Qualified film, television, or live theatrical productions.

Asset Placed in Service Date	Bonus Depreciation Rate	Strategic Implication
Jan 1, 2025 – Jan 19, 2025	40%	Consider using Section 179 to cover the remaining balance if eligible.
Jan 20, 2025 – Dec 31, 2025	100%	Immediate full write-off. Ideal for high-profit years to minimize taxable income.

Scenario 1: The Tech Startup Server Upgrade

Context: “AlphaTech LLC,” a software development firm, purchased $200,000 worth of new servers.

• Case A: The servers were installed and operational on January 10, 2025.
  Result: AlphaTech can claim 40% bonus depreciation ($80,000). The remaining $120,000 must be depreciated over the standard recovery period (typically 5 years for computers), unless Section 179 is used.
• Case B: The servers were installed on February 1, 2025.
  Result: AlphaTech claims 100% bonus depreciation ($200,000). The entire cost is written off in 2025, significantly lowering their net income.

The New 2025 SALT Deduction Rules

For LLC owners, who typically pass business income through to their personal returns, the State and Local Tax (SALT) deduction is a critical component of Year-End Tax Planning for LLC 2025. The OBBB Act has drastically raised the cap, providing relief to business owners in high-tax states.

Increased Caps and Phaseouts

For the 2025 tax year, the aggregate cap on SALT deductions (which includes state income taxes and property taxes) has been raised:

• Married Filing Jointly: $40,000 (up from $10,000).
• Married Filing Separately: $20,000.
• Single Filers: Implicitly $20,000 (based on the separate filer logic, though joint/separate are the explicitly defined statutory shifts in the OBBB Act).

However, this benefit comes with a “clawback” for high earners. The benefit is reduced by 30% of the amount by which the taxpayer’s modified Adjusted Gross Income (AGI) exceeds the applicable threshold:

• Phaseout Threshold (Joint): $500,000.
• Phaseout Threshold (Separate): $250,000.

Crucially, the law guarantees a minimum SALT deduction of $10,000 regardless of income. Even if the phaseout calculation would reduce the deduction to zero, the taxpayer is still entitled to the original $10,000 limit.

Scenario 2: The High-Earning Consultant

Context: Sarah and Mike file jointly. They live in New York and pay $45,000 in state income and property taxes. Their combined modified AGI for 2025 is $550,000.

1. Base Cap: $40,000.
2. Excess Income: $550,000 (AGI) – $500,000 (Threshold) = $50,000.
3. Reduction Calculation: 30% of $50,000 = $15,000.
4. Adjusted Cap: $40,000 – $15,000 = $25,000.

Result: Instead of deducting the full $40,000 cap, they can deduct $25,000. This is still significantly better than the previous $10,000 limit.

Scenario 3: The Ultra-High Earner

Context: Consider a couple with $800,000 in modified AGI and $60,000 in state taxes.

1. Excess Income: $800,000 – $500,000 = $300,000.
2. Reduction: 30% of $300,000 = $90,000.
3. Calculation: $40,000 (Cap) – $90,000 = -$50,000.

Result: Since the calculation drops below the floor, the guaranteed minimum applies. They can deduct $10,000.

Section 179: The Small Business Powerhouse

While Bonus Depreciation is excellent for large assets, Section 179 remains a precise tool for Small Business Tax Deductions 2025. The OBBB Act adjusted the limits to combat inflation and support small to mid-size enterprises.

• Maximum Deduction: $1,250,000.
• Investment Ceiling (Phaseout Start): $3,130,000.

Once a business places more than $3.13 million of qualified equipment into service, the deduction reduces dollar-for-dollar. This ensures the benefit targets small and medium businesses rather than corporate giants.

Strategic Use: Section 179 vs. Bonus Depreciation

Why use Section 179 when 100% Bonus Depreciation exists (post-Jan 19)?

1. Flexibility: Section 179 allows you to deduct a specific amount of an asset’s cost, whereas Bonus Depreciation is typically “all or nothing” for an asset class.
2. State Conformity: Many states do not conform to federal Bonus Depreciation rules but do conform to Section 179. Using Section 179 can align your federal and state tax returns, simplifying filing and reducing state tax liability.

Standard Deduction & Tax Brackets for 2025

Understanding the personal tax brackets is vital for LLC owners, as business profit is taxed at these individual rates.

Filing Status	Standard Deduction (2025)	Top Tax Rate (37%) Threshold
Single / Married Filing Separately	$15,750	Income > $626,350
Married Filing Jointly	$31,500	Income > $751,600
Head of Household	$23,625	(Varies by bracket structure)

Senior Deduction: For tax years 2025 through 2028, individuals age 65 and older can claim an additional $6,000 deduction per qualified individual, subject to income phaseouts starting at $75,000 (single) or $150,000 (joint). This is a crucial consideration for older business owners planning their retirement transition.

Common Pitfalls & Mistakes

Even with these generous LLC Tax Write-Offs 2025, errors can lead to audits or lost savings. Avoid these common traps:

1. Ignoring the “Placed in Service” Rule

Buying a piece of equipment on December 31, 2025, is not enough. It must be placed in service—meaning it is ready and available for use—before the year ends. If a machine is delivered in a box and not installed until January 2026, it does not qualify for the 2025 deduction.

2. Miscalculating SALT Phaseouts

High-income LLC owners often assume they get the full $40,000 SALT deduction. Failing to calculate the 30% reduction on excess income can lead to underpayment penalties. Always run the projection if your joint income exceeds $500,000.

3. Double Dipping

You cannot use Section 179 and Bonus Depreciation on the same portion of an asset’s cost. Generally, you apply Section 179 first, and then apply Bonus Depreciation to any remaining basis. Ensure your accountant follows this order of operations.

Frequently Asked Questions (FAQ)

1. Can I claim 100% bonus depreciation on a vehicle purchased in January 2025?

It depends on the specific date. If the vehicle was placed in service on or before January 19, 2025, you are limited to 40% bonus depreciation. If it was placed in service after that date, you may be eligible for 100% bonus depreciation, provided the vehicle meets the gross vehicle weight rating (GVWR) requirements (generally over 6,000 lbs) and business use criteria.

2. Does the new SALT cap apply to my business taxes?

The SALT cap applies to state and local income and property taxes paid by individuals. Since LLCs are pass-through entities, the business income is taxed on your personal return, and the state income tax you pay on that profit is subject to the cap. However, many states have enacted “Pass-Through Entity Tax” (PTET) elections that allow the business to pay the tax directly, bypassing the federal SALT cap entirely. Consult your advisor to see if your state offers a PTET.

3. What happens to the SALT cap after 2025?

Under the OBBB Act, the SALT cap is scheduled to increase by 1% annually starting in 2026 through 2029. In 2030, without further legislation, it is set to revert to the pre-2025 level of $10,000.

4. Are there new rules for claiming tips in 2025?

Yes. Notice 2025-69 offers specific guidance for individuals claiming deductions for qualified overtime and qualified tips for the tax year 2025. If your LLC operates in the service industry (e.g., a restaurant), ensure your payroll systems are updated to track these categories accurately.

Conclusion

The 2025 tax year presents a unique window of opportunity for LLC owners. The reinstatement of 100% bonus depreciation after January 19 and the expansion of the SALT deduction to $40,000 provide substantial levers to lower tax liability. However, the complexity of the bifurcated depreciation schedule and the income-based SALT phaseouts demands precise planning.

As we close out the year, review your asset acquisition logs and income projections immediately. Strategic purchases made now—specifically ensuring they are placed in service before December 31—can yield significant returns when you file. Always consult with a qualified tax professional to apply these rules to your specific business situation.