Written by Behdad Karimi Dermeni, CPA · Reviewed by Maryam Ajorloo, CPA
Every year, the same thing happens: the business runs fine for eleven months, then your accountant sends a friendly email asking for "a few documents," and suddenly you're digging through three inboxes, two bank apps, and a folder called "taxes FINAL (2)." This small business tax preparation checklist puts everything in one place, so tax season becomes a short errand instead of a scavenger hunt.
The short version: to prepare your small business taxes, you need closed-out books for the year, your profit and loss statement and balance sheet, every 1099 you received and issued, payroll forms, receipts for your larger expenses, a record of owner draws and estimated tax payments, and last year's return. The rest of this guide covers each item, plus the IRS due date for your type of business.
Most of that list comes straight out of your books, which is the good news. If your transactions are already sorted, half the checklist is just pressing "export." That's the part an AI Bookkeeper handles all year in the background, and we'll come back to how it shortens the rest.
The one rule behind every tax checklist
Here's the rule of thumb: your tax return can only be as accurate as the books underneath it. Your accountant isn't inventing numbers in April. They're taking your year of income and expenses, sorting them into the lines of a tax form, and applying the rules. If the books are complete and categorized, tax prep is quick. If they're not, your accountant spends billable hours rebuilding your year before the actual tax work starts.
So every item on this list is really one of two things: proof of what happened in your books, or a form someone else sent you that has to match them.
Start here: which return does your business file?
The checklist is mostly the same for every small business, but the form and the due date depend on how your business is set up. For calendar-year businesses:
Sole proprietor or single-member LLC: Schedule C, filed with your personal Form 1040. Due April 15.
Partnership or multi-member LLC: Form 1065, plus a Schedule K-1 for each partner. Due March 15.
S corporation (or an LLC taxed as one): Form 1120-S, plus a Schedule K-1 for each shareholder. Due March 15.
C corporation: Form 1120. Due April 15 (the 15th day of the 4th month after your year-end).
If a due date lands on a weekend or federal holiday, it moves to the next business day. The IRS keeps the full list in Publication 509, its tax calendar.
Notice that partnerships and S corps are due a month earlier. (That's not a typo. The IRS wants the K-1s out first, so the owners can file their own returns by April.) If you own one of these, your personal deadline effectively starts in March.
The small business tax preparation checklist
Work through these in order. The first two do most of the heavy lifting, because the rest of the list is checked against them.
1. Close out your books for the year
Before anything else, make sure the year is actually finished in your books:
Every business bank account, credit card, and payment processor (Stripe, PayPal, Square) is connected or imported, with no missing months.
Every transaction has a category. "Uncategorized" is not a tax category, as much as we'd all like it to be.
Business and personal transactions are separated. Anything personal that ran through the business account is recorded as an owner draw, not an expense.
You have the December statement for each account, so the year-end balances in your books match the bank.
You've used the same method all year. Most small businesses keep books on a cash basis, and switching midstream creates a mess (here's the difference between cash vs accrual accounting if you're not sure which you use).
If you're behind by more than a few months, start with our guide to catch-up bookkeeping before you tackle the rest of this list.
2. Pull your year-end financial statements
Once the books are closed, export three reports:
Profit and loss statement (also called an income statement): your total income and expenses for the year. This is the backbone of Schedule C or your business return. If the report looks like a wall of numbers, here's how to read a profit and loss statement in plain English.
Balance sheet: what the business owns and owes at year-end. Partnerships and corporations need it for the return; sole proprietors still benefit from it.
General ledger: the transaction-by-transaction detail behind both. Your accountant uses it to answer their own questions without emailing you.
With ReInvestWealth, all three come out of Financial Reports in a couple of clicks, already organized by category.
3. Gather your income forms (and check them against your books)
Collect every information return sent to you, and keep an eye out in January and February:
Form 1099-NEC from clients who paid you $2,000 or more for services. (For payments made in 2025 and earlier, the threshold was $600. The One Big Beautiful Bill Act raised it starting with 2026 payments.)
Form 1099-K from payment apps and marketplaces. These are only required once you pass $20,000 in payments across more than 200 transactions, but some platforms send them below that.
Form 1099-MISC for rent, prizes, or other payments, and Form 1099-INT for interest on business savings.
Then compare the totals to the income in your books. A 1099-K reports gross payments, before refunds and processing fees, so it will usually be higher than the revenue you recorded. That gap is normal. Just make sure your accountant can see where it comes from, and that a payment isn't counted twice (once on a client's 1099-NEC and again on a 1099-K).
Remember too: income is taxable whether or not anyone sends you a form.
4. Organize receipts and expense records
You don't need to print anything, but you do need proof behind your deductions, especially the big ones:
Receipts for larger purchases, travel, meals, and anything unusual.
A mileage log if you use a vehicle for business (dates, destinations, purpose, miles).
Your home office square footage and total home square footage, if you claim the home office deduction.
Purchase documents for equipment, computers, furniture, and vehicles bought this year.
This is where a digital receipt trail pays for itself. Receipts sent to the Smart Shoebox (your receipt inbox) get read by AI and matched to the bank transaction they belong to, so the proof is already attached when your accountant asks. For a refresher on what actually counts, see our guide to small business tax deductions.
5. Collect payroll and contractor forms
If you pay people, the forms you sent are part of your tax file too:
W-2s and W-3 for employees, plus your quarterly Form 941 filings and annual Form 940 (federal unemployment).
Form 1099-NEC copies for every contractor you paid $2,000 or more in 2026 (again, $600 for 2025 payments), along with their Form W-9.
W-2s and 1099-NECs are due to workers and the IRS by January 31, which is much earlier than your own return. If you're not sure who gets which form, our 1099 vs W-2 guide breaks it down.
6. List owner draws, contributions, and owner pay
Money moving between you and the business needs its own line on the checklist, because it's taxed differently depending on your structure:
Owner draws (sole proprietors, partners, most LLCs) are not a business expense and do not reduce your profit.
Owner contributions, meaning money you put into the business, are not income.
S corporation owners need their W-2 salary and their distributions shown separately.
Retirement and health insurance: contributions to a SEP IRA or solo 401(k), and health insurance premiums you paid as a self-employed owner, often get deducted on your personal return rather than the business one, so list them separately.
Mixing these up is one of the most common reasons a P&L looks wrong at tax time. Here's more on how to pay yourself from an LLC or S corp.
7. Record your estimated tax payments
If you paid quarterly estimated taxes, list the date and amount of each one. For a calendar year, they're due April 15, June 15, September 15, and January 15 of the following year. That January payment is the one people forget to mention, mostly because it feels like it belongs to the new year. It doesn't. (Tax deadlines have never respected the holiday mood.)
Your IRS online account shows every payment the IRS has on file, which is the fastest way to confirm the list is complete.
8. Pull loan, asset, and big-ticket records
Year-end statements for any business loans or lines of credit (the interest is deductible, the principal repayment is not).
Records of any business assets you sold, traded, or stopped using.
Lease agreements for vehicles, equipment, or office space signed this year.
9. Find last year's return and any IRS letters
Your accountant will want last year's return for carryovers (like depreciation and losses), and any notices or letters the IRS sent during the year. If a letter is sitting unopened in a drawer, now is the moment.
10. Confirm the basics
Your EIN, your entity's formation details, any change of address or ownership during the year, and the bank account you want a refund deposited into. Small stuff, but it's the stuff that stalls a return on the last day.
That's the whole checklist. Look back at it and you'll notice that steps 1 to 4 and 6 are all, essentially, "have clean books." That's exactly what ReInvestWealth's AI Bookkeeper does for you all year: it connects your bank, categorizes every transaction, and matches your receipts, so tax time starts at step 5. Start free for 30 days.
A small business tax prep timeline
A checklist is easier when it's spread over a few months instead of one weekend. Here's a calendar-year rhythm:
October to December: make sure the books are caught up through the fall, talk to your accountant about any year-end purchases or retirement contributions, and collect W-9s from any contractor you haven't yet.
January: close December in your books, send W-2s and 1099-NECs by January 31, and make your fourth-quarter estimated payment by January 15.
February: watch for incoming 1099s, pull your financial statements, and send your accountant the package.
By March 15: partnership and S corporation returns are due (or file an extension).
By April 15: sole proprietor and C corporation returns are due, along with the first estimated payment for the new year.
An extension (Form 4868 for individuals, Form 7004 for businesses) gives you six more months to file, not to pay. Any tax owed is still due by the original deadline. If you're curious what being late actually costs, our free IRS penalty and interest calculator does the math.
How to hand off to your accountant without 40 follow-up emails
Your accountant is on your side here. The cleaner the package, the more of their time goes to the valuable part (planning, deductions you might be missing, how to set up next year) instead of chasing paperwork. A good handoff includes:
The three financial statements from step 2, as PDFs or CSV exports.
One folder with every form from steps 3 and 5, named clearly.
A short note listing anything unusual: a big purchase, a new state, a new partner, a loan, a move.
Even easier: invite your accountant into your ReInvestWealth account so they can see the books directly, with their own login. No zipped folders, no "which version is this?"
How long to keep your tax records
Once the return is filed, don't delete anything. The IRS generally expects you to keep records for 3 years from the date you filed. Keep them for 4 years for employment tax records, 6 years if you left out more than 25% of your gross income, and 7 years if you claimed a loss from bad debt or worthless securities. If a return was never filed, there's no time limit at all. The details are on the IRS page on how long to keep records.
Records for assets you still own (like equipment you're depreciating) stay until a few years after you sell them. And if the idea of an audit makes your stomach drop, it shouldn't: here's how far back the IRS can actually audit a business, and why organized records make that question a lot less interesting.
4 mistakes that slow down tax prep
Counting a credit card payment as an expense. One thing we hear often from customers: they see a big monthly payment to their business card and categorize it as an expense. The expenses are the individual purchases on the card. The payment just moves money from the bank to the card, so counting it too doubles your deductions on paper (and your accountant will catch it, at an hourly rate).
Booking owner draws as expenses. It shrinks your profit in your books, but not on your return, so the numbers stop matching.
Adding a 1099-K on top of income you already recorded. The same sale can show up in your books and on a 1099-K. Count it once.
Starting in April. Turns out "I'll deal with it in April" is not a bookkeeping strategy. Two hours a month beats a lost weekend in spring.
Practical tips to make next year easier
Close each month, not just the year. A quick monthly look at your P&L means year-end is just one more month.
Keep one business account and one business card. Every personal charge you keep out of them is one less question at tax time.
Let the routine work run itself. Connect your bank to ReInvestWealth and the AI categorizes transactions and matches receipts as they come in, so most of this checklist is ready before anyone asks.
Frequently asked questions
What documents do I need to file small business taxes?
You need your year-end profit and loss statement and balance sheet, every 1099 you received (1099-NEC, 1099-K, 1099-MISC, 1099-INT), copies of the W-2s and 1099-NECs you issued, payroll filings, receipts for larger expenses, a mileage log if you drive for business, records of estimated tax payments and owner draws, loan statements, and last year's tax return.
When should I start preparing my small business taxes?
Start in the fall, not the spring. Catch your books up by October, collect contractor W-9s before year-end, and close December in early January. That leaves time to issue W-2s and 1099-NECs by January 31 and to send your accountant a complete package in February.
What if my 1099-K doesn't match my books?
That's common. A 1099-K reports gross payments before refunds, chargebacks, and processing fees, so it's often higher than the revenue in your books. Keep your records showing the refunds and fees, and make sure income isn't counted twice when a client also sent you a 1099-NEC for the same work.
Does a tax extension give me more time to pay?
No. Form 4868 (individuals) and Form 7004 (businesses) give you six more months to file your return, but any tax you owe is still due by the original deadline. Paying an estimate by that date limits penalties and interest even if the return itself comes later.
Can I prepare my small business taxes myself?
Many sole proprietors with simple books do. Partnerships and corporations usually work with an accountant because of K-1s and more complex rules. Either way, the checklist is the same, and the work is much faster when your books are already categorized and up to date.
Turn tax season into a short errand
You could rebuild your year from bank statements every spring, armed with a spreadsheet and a strong coffee. Or you could connect your bank once, let the AI Bookkeeper categorize every transaction as it happens, and send your accountant clean books in February. Built by CPAs, with CPA-level clean books and 30 days free. Start for free.
A note from our CPAs: This checklist is educational and covers the general federal rules for US small businesses. Tax situations vary, and your state may have its own requirements, so for advice on your specific circumstances, talk to your accountant. (If they use ReInvestWealth, they'll already have clean books to work from.)
Written by Behdad Karimi Dermeni, CPA
Co-founder of ReInvestWealth and a founding community builder at Stripe. Behdad built ReInvestWealth to give smart, busy entrepreneurs CPA-level accounting without the CPA-level price tag. Read more · Connect on LinkedIn
Reviewed by Maryam Ajorloo, CPA
Maryam Ajorloo is the co-founder of ReInvestWealth and a CPA who specializes in small business tax and everyday bookkeeping. She helps entrepreneurs keep clean, audit-ready books and make sense of write-offs, filing deadlines, and the numbers behind their business. Read more · Connect on LinkedIn
