Tax Reference

Business & Entity Tax

Entity selection, pass-through taxation, QBI, payroll obligations, executive compensation, and business deductions.
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The tax treatment of a business depends entirely on its entity structure. The same $300,000 of profit faces dramatically different tax outcomes depending on whether it flows through a sole proprietorship, S-corporation, partnership, or C-corporation. This section covers entity selection, the mechanics of each structure, and the deductions and credits available to businesses.

Entity Selection & Comparison
Guide
Business Entity Comparison
Full 12-factor comparison: sole prop, LLC, S-corp, C-corp, partnership.
Guide
S-Corp vs. LLC
SE tax savings, QBI interaction, compliance costs.
Guide
S-Corporation Basics
§1362 election, basis, BIG tax, AAA, §1375.
Guide
Partnership Tax Basics
§704(b) allocations, outside basis, §754 elections.
Guide
S-Corp Compensation
Reasonable salary, FICA optimization, distributions.
Guide
Form 7203 S-Corp Basis
Stock and debt basis tracking under IRC §1366/§1367. Loss limitation stacking, debt basis restoration, AAA vs basis.
Income & Deductions
Guide
QBI Deduction (§199A)
20% deduction, W-2 wage limits, SSTB classification.
Calculator
QBI Calculator
Estimate your §199A deduction.
Guide
Meals & Entertainment
50% limit, business meal rules, post-TCJA.
Calculator
Home Office Deduction
Simplified vs. actual method, exclusive use test.
Guide
Bonus Depreciation
100% permanent under OBBBA, §168(k), qualifying property.
Guide
R&D Tax Credit
IRC §41, four-part test, documentation requirements.
Guide
§163(j) Business Interest Limit
OBBBA EBITDA restored 2025. $31M small biz exception. 2026 capitalization rule, partnership EBIE allocation.
Guide
Form 461 Excess Business Loss
§461(l) permanent under OBBBA §70601. 2026 reset DOWN: $256K/$512K thresholds. Loss aggregation, NOL carryforward, W-2 wage trap.
Guide
§179 Expensing OBBBA Permanent
2026 cap $2,560,000 / phaseout $4,090,000 / full phase-out $6,650,000. OBBBA §70302 permanently doubled baseline. Heavy SUV $32,000. Applied BEFORE 100% bonus depreciation. §163(j) treats as amortization.
Guide
§168(n) Qualified Production Property
OBBBA §70307 created new §168(n) - 100% deduction for qualified production property (factories, refineries, agricultural/chemical production). Construction 1/20/2025-12/31/2028; placed in service through 12/31/2030. §1245 recapture. 95% de minimis. Notice 2026-16.
Guide
OBBBA §174A R&D Expensing + Form 3115
OBBBA created §174A for permanent domestic R&D expensing (2025+). Foreign R&D still 15-year. Small business retroactive election to 2022-2024 via §448(c) $31M test. Rev. Proc. 2025-28 procedures. Statement in lieu of Form 3115. §481(a) catch-up. §280C(c) credit coordination. AAR for BBA partnerships. 7/6/2026 deadline.
Guide
§461(l) Excess Business Loss: OBBBA Permanent
OBBBA made §461(l) permanent (no 2028 sunset). 2025: $313K single / $626K MFJ. 2026 RESET: $256K / $512K (base year reset to 2024 - approximately 18% lower than 2025). W-2 wages NOT business income. §1231 gains expand cap. NOL conversion at 80% limit. Form 461 mechanics. Order of limitations after basis, at-risk, passive. Equipment leasing tax shelter traps. Aggregation across pass-throughs codified.
Guide
Schedule K-1: Partnership, S-Corp & Trust K-1 Tax Reporting (2026)
Schedule K-1 guide: how to read and report K-1 income from partnerships (Form 1065), S-corporations (Form 1120-S), and trusts and
Payroll & Compliance
Guide
Payroll Tax Guide
FICA, FUTA, §6672 trust fund penalty, worker classification.
Guide
Executive Compensation
ISOs, NSOs, RSUs, §83(b), §409A.
Guide
Form 3115 / §481(a)
Accounting method changes, catch-up adjustments.
Guide
OBBBA Tax Changes
All 2025 OBBBA provisions affecting businesses.
Guide
Business Sale Planning
§338(h)(10), asset vs. stock, §1060 allocation.
Industry Guides
Guide
Agriculture & Farming Tax: Schedule F, Cash Method, Depletion & §1231 (2026)
Tax guide for farmers and agricultural businesses: Schedule F income and expenses, cash method of accounting for most farms, prepa
Guide
Tax Guide for Artists, Performers & Athletes: Schedule C, State Allocation & NIL Income (2026)
Tax guide for creative professionals and athletes: Schedule C vs. hobby loss rules, the 3-of-5-years profit test, state income tax
Guide
Business Travel Deduction: What Qualifies, What Doesn't (2026)
Business travel tax deduction guide: away-from-home test, primary purpose rule, transportation vs lodging vs meals (50%), combined
Guide
Dental & Medical Practice Tax: Entity Structure, Goodwill & Buy-In/Buy-Out (2026)
Tax guide for dental and medical practices: entity choice (PC vs. PLLC vs. S-corp vs. C-corp), personal goodwill vs. enterprise go
Guide
E-Commerce & Marketplace Seller Tax: Sales Tax Nexus, Inventory & Income (2026)
Tax guide for e-commerce sellers and Amazon/Shopify merchants: Wayfair economic nexus for online sellers, marketplace facilitator
Guide
Franchise Business Tax: Fees, Royalties, Area Developer Agreements & Multi-State (2026)
Tax guide for franchisors and franchisees: initial franchise fee treatment (amortize over 15 years vs. deduct), ongoing royalty pa
Guide
Staffing Agency & Gig Platform Tax: Worker Classification, Gross Receipts & Pass-Through (2026)
Tax guide for staffing agencies and gig platforms: the worker classification stakes for staffing agencies, gross receipts vs. net
Guide
Tech Startup Tax: R&D Credits, §1202 QSBS, Equity Compensation & §174A (2026)
Tax guide for technology startups: R&D tax credit mechanics under §41, §174A capitalization of R&D costs under OBBBA, §1202 QSBS $
Guide
Trucking & Transportation Tax: Owner-Operators, Per Diem & IFTA (2026)
Tax guide for trucking and transportation businesses: owner-operator vs. employee driver classification, per diem deduction for ov
Additional Resources
Guide
Controlled Groups §1563
Related entities treated as one for retirement limits, §179.
Guide
S-Corp Tax Guide
Pass-through, reasonable comp, W-2/K-1 split, built-in gains.
Guide
Crowdfunding Tax
Reward vs. equity crowdfunding; income recognition rules.
Guide
UBIT - Nonprofit Tax
When nonprofits owe corporate tax; three-part test.
BREAKING
ERC Update
Employee Retention Credit status, audits, repayment programs.
Employee & Contractor Issues
Guide
Worker Classification
Employee vs contractor - Rev. Rul. 87-41, §530 relief, misclassification penalties, Form SS-8.
Guide
Gig Worker / 1099
Schedule C, 15.3% SE tax, quarterly estimated payments, deductions.
Guide
W-2 vs. K-1: Employee vs. Business Owner Tax Income Explained (2026)
W-2 vs K-1 comparison: how employee wages differ from pass-through business income, withholding vs estimated tax, SE tax on K-1 ea
Advanced Planning
Guide
Installment Sales §453
Gross profit ratio, §453A interest charge on deferred gain, related party 2-year rule.
Guide
State PTET Elections
SALT workaround under Notice 2020-75 - NY/CA/NJ mechanics, OBBBA $40K cap.
Guide
Net Operating Loss
§172 indefinite carryforward, 80% taxable income cap, farming carryback exception.
Guide
R&D Deduction §174A
OBBBA restores immediate domestic R&D expensing, §280C(c) credit coordination.
Guide
§754 / §743(b) / §734(b): Partnership Basis Adjustments
Section 754 election complete mechanics. Single irrevocable election covers §743(b) (transfer of partnership interest) AND §734(b) (distribution to partner). TCJA substantial built-in loss §743(d) MANDATORY adjustment (>$250K basis over FMV OR transferee allocated loss >$250K) even without §754 election. §708(b)(1)(B) technical termination REPEALED. T.D. 10024 (January 10, 2025) related-party reportable transactions $5M threshold. Otay Project LP T.C. Memo 2026-21 economic substance denial. §755 capital gain class vs ordinary class allocation. §197 intangibles 15-year transferee amortization. Death-triggered §1014 coordination.
Guide
§382 NOL Limitation on Ownership Change
Section 382 complete mechanics. Limits pre-change net operating losses, capital loss carryforwards, and §163(j) carryforwards (post-TCJA addition by §13301) after ownership change. Ownership change §382(g)(1) = increase of more than 50 percentage points in stock held by 5-percent shareholders over 3-year testing period. §382 limitation = VALUE of loss corporation immediately before change × long-term tax-exempt rate (published monthly; ~4% range 2026). NUBIG/NUBIL 5-year recognition period - NUBIG increases limit when recognized; NUBIL recognized as pre-change loss subject to limitation. §382(c) Continuity of Business Enterprise - 2-year continuation required; failure = TOTAL DISALLOWANCE of pre-change losses. §382(l)(1) anti-stuffing capital contributions. §382(l)(5) bankruptcy exception with 50% NOL haircut for post-petition interest. §382(l)(6) alternative bankruptcy stepped-up value rule. §383 applies similar limits to credit carryforwards. Acquisitive reorganization coordination.
Guide
§351 Transfer to Controlled Corporation
Section 351 complete mechanics. Foundational nonrecognition provision for incorporating a business or transferring property to a controlled corporation. §351(a) general rule - no gain or loss when one or more persons transfer property to a corporation SOLELY in exchange for stock IF transferors are in CONTROL immediately after (§368(c) - 80% combined voting power + 80% of each nonvoting class). Property includes cash, real estate, equipment, intangibles - but NOT services (stock for services = §83 compensation; service-only shares don't count toward 80% test; Rev. Proc. 77-37 10% safe harbor). Boot §351(b) - anything other than stock; gain to LESSER of boot FMV or realized gain; loss never recognized. Liabilities assumed §357 - (a) generally not boot; (b) tax-avoidance liabilities = boot; (c) liabilities exceeding aggregate basis = gain recognized. Basis §358(a)(1) substituted to transferor; §362(a) carryover plus gain recognized to corporation. §362(e)(2) anti-loss-duplication; §362(e)(2)(C) transferor election to step down stock basis instead. Investment company exception §351(e). Nonqualified preferred stock §351(g) treated as boot. Statement Reg §1.351-3 required from both sides.
Guide
§197 Goodwill and Intangibles Amortization
Section 197 complete mechanics. Uniform 15-year straight-line amortization of acquired intangibles used in trade or business; replaced pre-1993 useful-life disputes. 14 categories §197(d): goodwill, going concern value, workforce in place, information base, know-how, customer base, supplier base, licenses and permits, covenants not to compete, franchises, trademarks, trade names. Must be ACQUIRED after August 10, 1993 in connection with trade or business §197(c)(1). Self-created intangibles excluded §197(c)(2) - EXCEPT self-created in connection with business acquisition (covenant not to compete given to seller). 15-year period APPLIES REGARDLESS of actual useful life (4-year non-compete still amortized over 180 months). Anti-churning §197(f)(9) - cannot convert pre-Aug 11, 1993 nonamortizable intangibles into amortizable §197 status via related-party transactions or tax-free reorgs; Reg §1.197-2(h). Excluded from §168(k) bonus depreciation AND §179 expensing. §197(f)(1) loss disallowance on single-asset disposition if other §197 intangibles from same acquisition retained - disallowed loss increases basis of retained intangibles. §1060 / Form 8594 purchase price allocation residual method. American Jobs Creation Act 2004 repealed §197(e)(6) sports franchise exclusion.
Guide
§1377 / §1368 S-Corp Allocations and Distributions
Section 1377 and Section 1368 complete mechanics. §1377(a)(1) DEFAULT per-share, per-day allocation - shareholder's share computed by days held and shares held (daily proration of all pass-through items). §1377(a)(2) CLOSING-OF-BOOKS ELECTION on full shareholder termination - year treated as two taxable years; pre-termination items allocated based on actual results; requires unanimous consent of "affected shareholders" (terminating + transferees). Reg §1.1368-1(g)(2) QUALIFYING DISPOSITION ELECTION for 20%+ disposition or 25%+ new issuance - similar closing-of-books treatment; all year-shareholders must consent; §1377(a)(2) trumps where both apply. §1368 DISTRIBUTION ORDERING: S corp without C corp E&P → reduces basis tax-free; excess capital gain. With C corp E&P → (1) AAA tax-free to basis, (2) PTI, (3) C corp E&P as §301 dividend, (4) remaining basis, (5) capital gain. AAA per Reg §1.1368-2 - adjusted by income/loss/distributions; can go negative from losses only, not distributions. §1368(e)(3) E&P-first election (bypass AAA). §1377(b) POST-TERMINATION TRANSITION PERIOD - day after termination through later of 1 year or final return due date; §1371(e) cash distributions from AAA retain S-corp treatment. §1374 BIG sting tax and §1375 excess passive income coordination.
Guide
Partnership §754 Election: Inside Basis Step-Up on Transfers & Deaths
Section 754 election guide: what the §754 election does, how §743(b) adjustments work when a partnership interest is sold or trans
Guide
Valuation Allowance Guide: ASC 740 Positive & Negative Evidence
ASC 740 valuation allowance: the more-likely-than-not standard, positive and negative evidence, the cumulative loss presumption, r
BREAKING
Cannabis & §280E
DOJ/DEA rescheduled medical cannabis April 22 2026. §280E eliminated for licensed medical.
Guide
Captive Insurance & §831(b)
$2.9M limit, Jan 2025 final regs, Apr 2026 TX court vacatur, circuit split.
Guide
§409A Deferred Compensation
6 permissible triggers, 20% excise tax penalty, stock option valuation.
Guide
§501(c)(3) Tax-Exempt Organizations
Organizational test, UBIT §511-513, private foundation excise taxes.
Guide
§368 Tax-Free Reorganizations
Types A/B/C/D, continuity of interest, boot recognition, step transaction.
Guide
§302 Corporate Redemptions
Capital gain vs. dividend, §318 attribution trap, complete termination waiver.
Guide
Oil & Gas Tax
15% percentage depletion, IDC immediate deduction, working interest exception.
Guide
Construction: PCM vs. CCM
§460 long-term contracts, $30M small contractor exception, look-back interest.
Guide
SaaS Sales Tax
Wayfair economic nexus, taxability by state, B2B exemptions.
Guide
Reinsurance Tax
§845 reallocation authority, BEAT on offshore premiums, ECI analysis.
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