Individual and Business Tax Returns

What is a tax return? A tax return is the form or set of forms you file with the IRS to report income, claim deductions and credits, and determine whether you owe tax or are due a refund. Tax filing is the legal process by which individuals and businesses report income and pay taxes on time.

Form 1040 - Individual Tax Return

Form 1040 is the federal personal tax return used to report wages, interest, dividends, capital gains, retirement distributions, rental income, and any business income reported by a sole proprietor (Schedule C). It calculates your income tax and applies deductions and credits to determine whether you must pay taxes or receive a refund.

Key components:

Income reporting
W-2 wages, 1099 income, interest and dividends, capital gains, retirement distributions, rental and business income.

Adjustments
Retirement contributions, student loan interest, educator expenses, and self-employment deductions.

Deductions & credits
Standard deduction or itemized deductions (Schedule A) and credits such as the child tax credit or education credits.

Additional taxes
Self-employment tax, alternative minimum tax, where applicable.

Common supporting schedules quick guide: Schedule C (sole proprietor business income and expenses), Schedule E (rental and royalty income), Schedule D (capital gains), Schedule A (itemized deductions), Schedule B (interest and dividends). If you are a sole proprietor, your business income flows to Schedule C and then to Form 1040.

Practical example W-2 earner vs. sole proprietor: A W-2 employee with $70,000 wages and standard deduction typically reports wages on Form 1040 and claims credits/deductions there. A sole proprietor with $100,000 gross receipts and $40,000 deductible expenses reports net business income ($60,000) on Schedule C, then on Form 1040; they must also account for self-employment tax and estimated tax payments.

Filing deadlines & action items: Individuals typically must file by April 15 (dates may shift for weekends/holidays). If you receive business or rental income, track your expenses, retain receipts, and consider quarterly estimated tax payments to avoid underpayment penalties. If you need help preparing a personal tax return or handling personal business taxes, consult a tax professional.

Business Tax Returns

Choose the return that matches your legal entity, partnerships (including multi-member LLCs) generally file Form 1065, C corporations file Form 1120, and S corporations file Form 1120S. Your business tax return determines how income is taxed (at the entity level or passed through to owners) and which tax forms and schedules you will need.

Which form applies to my business?

Single-member LLC or sole proprietor
Report business income on Schedule C of Form 1040 (see Individual Tax Return section).

Multi-member LLC / Partnership
File Form 1065; income flows through to partners via Schedule K-1.

S corporation
File Form 1120S; income, deductions, and credits pass through to shareholders (Schedule K-1).

C corporation
File Form 1120 and pay corporate tax on net income; dividends to shareholders can create double taxation.

Form 1065 – Partnership Return

Partnerships (including multi-member LLCs taxed as partnerships) must file Form 1065. The partnership itself files the return but generally does not pay income tax; income, deductions, and credits pass through to partners and are reported on each partner’s individual tax return via Schedule K-1.

Key features and why it matters:

Pass-through taxation: Form 1065 reports partnership-level items; each partner receives a Schedule K-1 showing their share of business income, deductions, and credits to report on their Form 1040.
Partner reporting: Partners include K-1 items on their personal tax returns, which affects personal tax, personal income reporting, and any required pay or estimated tax obligations.
Filing deadline: Form 1065 is generally due March 15 (the 15th day of the third month after year-end); file Form 7004 to request an extension.
Complexity & recordkeeping: Partnerships must track allocations, guaranteed payments, partner capital accounts, and business expenses carefully to support K-1 allocations and deductions.

Practical example: Two partners split profits 60/40. The partnership reports $200,000 net business income on Form 1065. Partner A’s K-1 will show $120,000 (60%) and Partner B’s K-1 will show $80,000 (40%); each partner reports their share on their Form 1040, paying tax at their individual income tax rates.

Common pitfalls and checklist:

Incorrect profit/loss allocations or failure to document partner agreements (maintain a written partnership agreement detailing allocations).
Missing guaranteed payments or not properly classifying owner draws versus deductible expenses.
Incomplete records for business income and expenses, keep receipts, bank statements, payroll records, and depreciation schedules.

If partnership allocations, multi-state income, or K-1 items are complex, consult a CPA experienced with partnerships to avoid costly reporting errors and ensure partners meet their personal tax filing and estimated tax obligations.

Form 1120 – C Corporation Return

C corporations file Form 1120. A C corporation is a separate legal entity that reports corporate income, deductions, and computes corporate tax liability on Form 1120, and corporate profits can be subject to double taxation when distributed as dividends to shareholders.

Key features:

Separate taxation: The corporation pays tax on its taxable income; shareholders pay tax on dividends, which can create double taxation on the same economic earnings.
Deductions and documentation: Common deductible items include salaries and wages, cost of goods sold (COGS), rent, professional fees, depreciation, and other ordinary business expenses. Retain payroll records, expense receipts, and depreciation schedules to substantiate deductions.
Filing deadline: Calendar-year C corporations generally file Form 1120 by April 15 (fiscal-year corporations file by the 15th day of the fourth month after year-end); extensions are available via Form 7004.
Detailed reporting: Form 1120 requires schedules for dividends, capital gains, tax credits, and various adjustments to reconcile book income to taxable income.

When to consult a tax advisor: If your corporation has complex items (significant depreciation, intercompany transactions, multi-state activity, or questions about shareholder distributions and reasonable compensation), work with a CPA or Accounting Firms to optimize deductions, ensure compliance, and review payroll and owner compensation strategies to balance corporate tax and owner-level tax consequences.

Form 1120S – S Corporation Return

S corporations elect pass-through taxation and file Form 1120S. The entity itself generally does not pay federal income tax; instead, income, deductions, and credits flow through to shareholders via Schedule K-1 and are reported on each shareholder’s Form 1040.

Key features and compliance points:

Pass-through treatment: Like partnerships, an S corp’s income, losses, deductions, and credits pass through to owners; each shareholder receives a Schedule K-1 reporting their share of the business’s income, losses, deductions, and credits.
Shareholder reporting: Shareholders include K-1 items on their personal tax returns, which affects their personal taxes and potential required estimated tax payments.
Filing deadline: Form 1120S is generally due March 15 (the 15th day of the third month after year-end); file Form 7004 to request an extension.
Eligibility and restrictions: S corporations are subject to limits on the number and types of shareholders (generally U.S. persons, with a statutory cap on shareholders); they cannot have multiple classes of stock in most cases.

Practical considerations for owners: S corporation owner-employees must be paid reasonable compensation for services performed; payroll and employment tax compliance are essential. Profits distributed as shareholder distributions are generally not subject to payroll taxes but are reported on a K-1 and taxed at the shareholder level.

Example: S corp vs. C corp on owner compensation: An owner who works in the business should receive a salary (subject to payroll taxes) and may also receive distributions. Compared with a C corporation, an S corp typically avoids entity-level tax on distributions but requires careful documentation of reasonable compensation to withstand IRS scrutiny.

If your S corporation has payroll issues, complex shareholder allocations, or multi-state income, consult a CPA to ensure proper payroll withholding, optimize tax outcomes, and keep records to support K-1 reporting for owners and the business.

Important Considerations for Both Individual and Business Returns

How long should I keep tax records?

Good recordkeeping is the foundation of accurate tax filing. The IRS generally recommends keeping records for 3 years (from the date you filed) for most items, but some situations require longer retention, up to 7 years for certain loss or bad-debt claims, and indefinitely for records related to basis in property. For business owners and partnerships, retain payroll records, depreciation schedules, bank statements, receipts for significant expenses, and partnership/corporate documents.

Keep at least 3 years for most tax returns; keep 6–7 years if you underreport income by more than 25% or if you claim a loss from worthless securities.
Keep employment tax records for at least 4 years after the date the tax becomes due or is paid, whichever is later.
For business tax and partnership records (K-1 support, contracts, capital account records), maintain organized files and backups for 7 years when feasible.

When must I make estimated tax payments?

If you are an owner of a pass-through entity, a sole proprietor, or have significant non-wage income, you may need to make quarterly estimated tax payments to avoid underpayment penalties. Estimated taxes cover income tax and self-employment tax (for sole proprietors) or owner-level tax liabilities resulting from pass-through business income.

Individuals generally pay estimated taxes quarterly (April, June, September, January). If you expect to owe $1,000 or more when you file, consider paying estimates.
Owners receiving K-1 income should calculate expected personal tax and make estimated payments to cover taxes on pass-through business income.
Business owners: include both income tax on personal returns and, if applicable, self-employment tax when estimating required pay amounts.

How should I plan to reduce taxes and maximize deductions?

Effective tax planning means timing income and deductions, maximizing available credits, and choosing the right entity and filing approach for your situation. For business owners, proper classification of expenses and consistent bookkeeping will preserve deductible items and protect against IRS adjustments.

Use ordinary and necessary tests: document business expenses (meals, travel, home office if eligible, supplies) and retain receipts to substantiate deductions.
Consider entity structure: pass-through entities (partnerships, S corps) shift tax to owners but may increase owner-level tax obligations; C corporations face entity-level tax but can provide planning flexibility for retained earnings.
For personal business taxes, track business income separately and reconcile bank accounts monthly to support deductions and prepare accurate tax forms.

What are the key compliance items to avoid penalties?

Timely filing and prompt responses to IRS notices are essential. Filing taxes late, underpaying estimated taxes, or failing to file required information returns (like K-1s) can trigger penalties and interest.

File returns and extensions on time, use Form 7004 for business extensions where applicable.
Respond within the notice deadlines and document all correspondence with tax authorities.
Stay informed about major tax law changes that affect filing, credits, or deduction limits for both personal and business income taxes.

When should I hire a CPA or tax professional?

Complex returns, multi-state business activity, significant pass-through income, payroll and owner compensation issues, or suspected IRS notices are situations where professional assistance provides clear value. A CPA or an Accounting Firm can help with entity selection, estimated tax calculations, payroll compliance, and the preparation of accurate tax returns and forms.

At The Chamberlain Accounting Firm, we are recognized as one of the leading accounting firms in Bergen County, New Jersey, serving clients in other towns across the county and in surrounding states. Our services encompass bookkeeping and accounting for law firms, general bookkeeping and accounting, as well as preparation of individual tax returns (Form 1040) and business tax returns for partnerships and corporations (Forms 1065, 1120, and 1120S). We are dedicated to helping law firms and businesses achieve financial accuracy, maintain compliance, and support growth wherever they are located. Contact us today or call us at (201) 464-1011 to learn how we can help your business maintain financial health and compliance.

Contact us

Where to Find Us

Westwood
381 Broadway, 2nd Floor
Westwood, NJ 07675

Phone: (201) 464-1011