An accountable plan is an employer expense-reimbursement arrangement with a business connection, timely substantiation and return of excess advances. Qualifying reimbursements generally are not employee wages.

Bonus Depreciation

Bonus depreciation is an accelerated deduction for qualifying property. A 100% allowance applies to eligible property acquired and placed in service after January 19, 2025, under current federal law.

Cost Segregation

Cost segregation identifies building components that qualify for shorter depreciation periods than the building itself. It changes deduction timing and requires support for the classifications and costs.

Estimated Quarterly Taxes

Estimated taxes are payments made during the year toward income tax and other applicable taxes when withholding does not cover the required amount.

Health Savings Account (HSA)

A health savings account provides federal tax advantages for eligible individuals with qualifying health coverage. Eligibility depends on coverage and other conditions, not simply paying your own premiums.

Home Office Deduction

A home-office deduction may apply when a qualifying area of a home is used regularly and exclusively for business. Special rules cover certain storage and daycare uses.

Limited Liability Company (LLC)

A limited liability company is a business entity formed under state law. Its federal tax classification can be a disregarded entity, partnership or corporation, depending on ownership and elections.

Net Operating Loss (NOL)

A net operating loss is a tax loss calculated under specific rules. It can sometimes be carried to another year, subject to limits; it is not simply negative cash flow or the loss on a profit-and-loss report.

Pass-Through Entity

A pass-through business generally reports income, deductions and other tax items to its owners for inclusion on their returns instead of paying ordinary federal corporate income tax on those earnings.

Qualified Business Income (QBI) Deduction

The qualified business income deduction can reduce taxable income for eligible pass-through business owners by up to 20% of qualified business income, subject to limits.

R&D Tax Credit

The research credit is a federal tax credit for qualifying research expenses under Section 41. Eligibility depends on the activity and expense rules, not the industry label or a company’s revenue alone.

Reasonable Salary (S-Corp)

Reasonable compensation is pay that reflects an S-Corp shareholder-employee’s services. Duties, time, experience and comparable market compensation help support the amount.

S Corporation

An S corporation passes most federal income-tax items through to its shareholders. An owner who works in the business generally receives reasonable wages before non-wage distributions.

SALT Deduction

The state and local tax deduction allows eligible itemizers to deduct certain income or sales taxes and property taxes, subject to an annual cap and income-based reductions.

Section 179 Deduction

Section 179 allows an election to expense eligible business property when it is placed in service, subject to purchase, business-use, annual and taxable-income limits.

Self-Employment Tax

Self-employment tax funds Social Security and Medicare on qualifying net earnings. The regular rates are 12.4% for Social Security up to the wage base and 2.9% for Medicare, with additional Medicare tax possible.

SEP IRA

A SEP is an employer-funded retirement arrangement. Contributions are limited by eligible compensation and an annual cap, with special calculations for self-employed owners.

Sole Proprietorship

A sole proprietorship is an unincorporated business owned by one individual. Its business income and expenses generally go on the owner’s individual income-tax return.

Solo 401(k)

A one-participant 401(k) is generally for a business owner with no eligible employees other than a spouse. Employee and employer contributions have separate rules and a combined annual limit.

Standard Mileage Rate

The standard mileage rate is an optional way to calculate eligible vehicle costs. For 2026 business driving, it is 72.5 cents per mile January through June and 76 cents July through December.

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