Find the rule. Read the source.
A curated route into the Internal Revenue Code, Treasury regulations, and federal and California guidance. These links open the original publishers.
What counts as gross income?
The starting point for identifying income before exclusions, deductions and other adjustments.
From gross income to adjusted gross income
Locate the deductions used to arrive at AGI; distinguish them from deductions taken later.
From AGI to taxable income
The statutory framework for taxable income, itemized deductions and the standard deduction.
Trade or business expenses
Study ordinary and necessary business expenses alongside capitalization and other limiting provisions.
Qualified business income deduction
The QBI deduction has its own definitions, thresholds and limitations; gross business receipts are not QBI.
The at-risk limitation
A separate potential restriction on losses; a positive tax basis does not settle the at-risk question.
Passive activity loss limits
Analyze activity classification and participation separately from basis and at-risk limits.
Who pays tax on partnership income?
The central pass-through rule: the partners, rather than the partnership, generally bear the income tax.
Separate items keep their character
Certain items pass through separately so the partner can apply the rules appropriate to that item.
Allocations and the basis loss limit
Connect the partnership agreement, substantial economic effect and the outside-basis limit on losses.
The outside-basis rollforward
Track adjustments to the partner’s tax basis for income, distributions, losses and specified expenditures.
Partnership tax years and timing
Follow the rules that connect the partnership’s year, the partner’s year and changes in ownership.
Partner transactions and guaranteed payments
Distinguish distributive shares, guaranteed payments and transactions outside the partner capacity.
Contributions and nonrecognition
Begin the analysis of a property contribution, then test for exceptions and related transaction rules.
Initial outside basis on contribution
The partner’s starting basis generally follows contributed cash and adjusted tax basis, subject to other rules.
The partnership’s basis in contributed property
Inside basis belongs to the partnership’s assets; it is distinct from a partner’s outside basis.
When a distribution triggers gain or loss
Cash, marketable securities and special distribution rules can make an otherwise simple withdrawal complex.
Basis of property received in a distribution
Current and liquidating distributions can produce different bases in the property received.
Outside basis after a distribution
Connect the amount and basis of distributed property to the reduction in the partner’s outside basis.
Sale of a partnership interest
Start with the general sale rule, then check § 751 for ordinary-income components.
Unrealized receivables and inventory
The hot-asset rules can change character on a sale or on certain disproportionate distributions.
Partnership liabilities and deemed cash
Changes in a partner’s share of liabilities can create deemed contributions or distributions.
The election linking transfers and inside-basis adjustments
Research the election together with §§ 734 and 743; an election is not the adjustment calculation itself.
Allocations and capital accounts
Read the detailed allocation rules and capital-account framework alongside § 704.
Contributed property and built-in gain
Explore the methods used to account for differences between book value and tax basis.
Transactions and guaranteed payments
The regulation supplies detail and examples for several categories of partner payments.
Distribution recognition rules
Read the regulatory examples and cross-references before treating a distribution as tax-free.
Classifying partnership liabilities
Definitions of recourse and nonrecourse liabilities lead to different allocation rules.
Entity classification and elections
The check-the-box regulation addresses default classification and elective changes for eligible entities.
Publication 541: Partnerships
A readable orientation to partnership tax concepts. Use the Code and regulations to support a legal conclusion.
Partner’s instructions for Schedule K-1
Interpret K-1 boxes and codes, with cross-references to partner-level reporting and limitations. Check the year shown.
Instructions for Form 1065
Partnership return filing and reporting instructions. The form revision and tax year matter.
Publication 505: Withholding and estimated tax
Explore withholding, estimated-payment methods and the assumptions behind underpayment calculations.
Estimated taxes: federal overview
Start here for individual and business estimated-payment concepts, then use the year-specific form instructions.
Understand an IRS notice or letter
Find the CP or LTR number, identify the tax period and preserve any response deadline.
Administrative penalty relief
Check the current relief program, qualifying penalties, compliance history and affected tax periods.
Business structures
Compare the broad federal tax categories before studying a specific entity or election.
Tax years and annual accounting periods
Distinguish calendar, fiscal and short tax years before selecting a form or applying a threshold.
Prior-year forms and instructions
Use the forms and instructions for the year being researched, rather than relying on the current page alone.
California LLC tax and fee framework
Study the annual tax and the separate income-based LLC fee, along with exceptions and filing duties.
California conformity to federal law
A federal tax change does not automatically determine the California result. Review the state’s specific treatment.
California residency: starting point
Residency and income sourcing are separate factual questions. Follow the linked residency guidance for detail.
California estimated tax payments
California installment percentages and safe-harbor limits differ from the federal rules.
California forms and publications
Find the appropriate tax year, return, instructions and supplemental state guidance.
Code, regulations and official guidance
A federal source map connecting the statute, Treasury regulations and published administrative guidance.
Understanding IRS guidance
Learn what revenue rulings, revenue procedures, notices and other guidance are intended to do.
Internal Revenue Bulletins
Browse the IRS publication used to announce official rulings, procedures and Treasury Decisions.
Authority and reliance: IRB guidance and FAQs
Understand why an IRS web explanation and a published ruling have different roles in research.
Official U.S. Code: Title 26
Cross-check the Internal Revenue Code in the government’s current preliminary edition and inspect source notes.