The Small Business Tax Prep Checklist Your CPA Wishes You Used

If tax season feels harder than it should, it’s usually not the math—it’s the missing information. This guide shows small business owners, side hustlers, and landlords exactly what to gather, how to organize it, and what to tell your CPA so your return is accurate, compliant, and on time.

Use the checklist below to prevent costly mistakes like unreported 1099 income, missed deductions, and IRS notices that can be avoided with better prep.

Start here: tell your CPA what changed

Even if your CPA filed your return last year, they need updates to file correctly this year. Share changes such as:

• Address, legal name, or bank account changes
• Marital status changes (married, divorced, separated)
• New or removed dependents
• Child and dependent care expenses (provider name, address, EIN/SSN, and total paid)
• New jobs, side businesses, or rental properties

These updates affect your filing status, credits, and what forms must be included.

Your tax prep checklist: documents to gather

Collect the right documents once and you’ll save hours of back-and-forth later. Use this table to verify what your CPA needs.

Self-employed or side hustle? Treat it like a real business

Taxes are owed on profit, not revenue—so you must track both income and expenses accurately. If you earn 1099 income (consulting, real estate, trades, creator work), you’ll generally file on Schedule C and may need to make quarterly estimated tax payments.

What your CPA needs beyond bank statements

Bank statements are not financial statements.

Your CPA needs:

• Profit & Loss (income and expenses summarized for the year)
• Balance Sheet (assets, liabilities, equity)
• General Ledger (detail of each transaction)

Use proper bookkeeping (e.g., QuickBooks) so transactions are categorized to the right accounts. Screenshots or raw statements show only fragments and lead to missed deductions or misstatements.

Common deductible expenses to organize

• Vehicle costs: track business mileage or actual expenses (gas, insurance, repairs)
• Home office: space used regularly and exclusively for business
• Supplies, software, subscriptions, phone/internet
• Advertising and marketing
• Professional fees (legal, accounting)
• Travel and meals (business purpose required)

If your 1099 income isn’t reported, the IRS can match payers’ forms to your return and send a notice. When that happens, the fix is often to amend and include both your income and legitimate expenses, which usually lowers the proposed tax bill.

1099 forms: what to send and why it matters

Most 1099s signal taxable income. Common types include:

• 1099-NEC: Nonemployee compensation (contract work)
• 1099-MISC: Rents and certain other income
• 1099-K: Payment apps and processors (threshold-based)
• 1099-G: Unemployment or state payments

Failing to include 1099 income often triggers an IRS underreporter notice proposing additional tax. Don’t panic: in many cases, documenting your expenses and amending the return corrects the balance to what you actually owe.

Rental property owners: capture the full picture

For each property, provide rent received and a detailed list of expenses (mortgage interest, taxes, insurance, repairs, HOA, utilities you pay, management fees). Your CPA also needs the purchase agreement or settlement statement to compute depreciation: date placed in service, purchase price, and allocated land value.

Depreciation is a non-cash expense that reduces taxable rental income each year. Keep accurate records from day one to avoid reconstruction later.

When losses may offset your wages

By default, rental losses are passive and usually can’t offset W-2 wages. If you legitimately qualify as a real estate professional and materially participate, some or all rental activity may be treated as nonpassive, allowing losses to offset other income. Eligibility depends on strict hour and participation tests—document time logs and duties if you pursue this.

Standard vs. itemized deductions: when Schedule A wins

For 2024, the standard deduction is $29,200 for married filing jointly and $14,600 for single filers. If your allowable itemized deductions exceed your standard deduction, itemizing may reduce your tax.

Common itemized deductions include:

• Mortgage interest (Form 1098)
• State and local taxes (subject to annual limits)
• Charitable contributions (keep receipts)
• Medical expenses above the applicable AGI threshold

Your CPA will compare both approaches and select the one that lowers your liability.

Home office deduction, done correctly

You may claim a home office if a space is used regularly and exclusively for business and is your principal place of business. Two calculation methods exist:

• Simplified: $5 per square foot, up to 300 sq. ft.
• Regular: Actual expenses multiplied by business-use percentage (rent or mortgage interest, utilities, insurance, repairs)

Good documentation makes this a legitimate deduction—not a red flag.

A 30-minute prep plan before you email your CPA

1. List your life and household changes for the year.
2. Download all tax forms from employer, bank, broker, and payroll/processor portals.
3. Export your Profit & Loss, Balance Sheet, and General Ledger from your bookkeeping system and reconcile bank/credit accounts through year-end.
4. List major asset purchases with date placed in service and cost.
5. Create a one-page worksheet per rental with rent and categorized expenses; attach closing documents for new properties.
6. Total child/dependent care expenses and capture provider EIN/SSN and address.
7. Estimate whether you’ll itemize or take the standard deduction; collect supporting receipts either way.
8. Send documents securely and ask targeted questions: quarterly estimates, home office qualification, vehicle method, and whether an S corporation election or payroll makes sense for your situation.

What success looks like

• Accurate, on-time filing with fewer follow-up questions
• Lower effective tax rate by capturing legitimate deductions
• No surprise IRS notices caused by missing 1099s
• Clean books that double as management tools, not just tax records

Bottom line

The right prep eliminates guesswork, prevents IRS letters, and reduces taxes you shouldn’t be paying. Use this checklist each year, keep clean books, and tell your CPA what changed before they start your return. It’s the fastest path to a smooth tax season.