To prepare an accurate return, your accountant needs identity information for everyone listed on the return, every income form you received during the year, records of the deductions and credits you plan to claim, and any documents unique to your situation (self-employment, investments, digital assets, foreign accounts, or estimated payments). So when a client asks what an accountant needs to do their taxes, the honest answer is: a complete picture of the year in paper form. The federal filing deadline for most individual returns is April 15, and the late-filing penalty runs 5% of unpaid taxes for each month the return is overdue, up to 25%.1Internal Revenue Service. Failure to File Penalty The more organized your handoff, the less time (and money) the process takes.
Identity and Household Information
Every person named on the return needs a valid taxpayer identification number. Federal law requires each person listed to provide an identifying number, which for individuals is their Social Security account number.2Office of the Law Revision Counsel. 26 USC 6109 – Identifying Numbers People who aren’t eligible for an SSN use an IRS Individual Taxpayer Identification Number (ITIN) instead.3eCFR. 26 CFR 301.6109-1 – Identifying Numbers Give your accountant full legal names and dates of birth for yourself, your spouse, and every dependent exactly as they appear on government documents. A single mismatched character can cause the IRS to reject the return.
If anyone on the return is enrolled in the IRS Identity Protection PIN program, share that six-digit number. An incorrect or missing IP PIN causes an e-filed return to be rejected or a paper return to be delayed.4Internal Revenue Service. Get an Identity Protection PIN A new PIN is issued every year, so make sure you’re providing the current one.
For direct deposit of any refund, provide your bank routing number and account number. If you paid a childcare provider and plan to claim the child and dependent care credit, you also need the provider’s name, address, and either their EIN or SSN. Missing or incorrect provider information can get the credit disallowed entirely.5Internal Revenue Service. 2025 Instructions for Form 2441, Child and Dependent Care Expenses
Income Documents
The IRS receives copies of most income forms and will flag anything missing from your return, so hand over documentation for every dollar you received, not just your paycheck.
- W-2 from every employer you worked for during the year.
- 1099-INT for interest of $10 or more from banks and credit unions on savings, CDs, and similar accounts.
- 1099-DIV for dividends from stocks and mutual funds.6Internal Revenue Service. About Form 1099-DIV, Dividends and Distributions
- 1099-B for sales of stocks, bonds, or mutual fund shares. This shows proceeds and, for covered securities, cost basis, which your accountant uses to calculate capital gains or losses.7Internal Revenue Service. Instructions for Form 1099-B (2026)
- 1099-R for pension, 401(k), and IRA distributions. Payouts taken before age 59½ generally trigger an additional 10% tax on top of regular income tax unless an exception applies.8Internal Revenue Service. Topic No. 557, Additional Tax on Early Distributions From Traditional and Roth IRAs
- 1099-G for unemployment compensation, which is taxable income and must be included in gross income.9Internal Revenue Service. Unemployment Compensation
- W-2G for gambling winnings. For 2026, the reporting threshold is $2,000, adjusted annually for inflation, with additional conditions for certain payout types (such as winnings being at least 300 times the wager for sports bets and horse racing). Winnings below the threshold are still taxable and should be reported to your accountant.10Internal Revenue Service. Instructions for Forms W-2G and 5754
If you have a Health Savings Account, provide Form 1099-SA (distributions) and Form 5498-SA (contributions and year-end balance).11Internal Revenue Service. About Form 1099-SA, Distributions From an HSA, Archer MSA, or Medicare Advantage MSA12Internal Revenue Service. Form 5498-SA (Rev. December 2026) The 5498-SA often arrives after the filing deadline, so keep your own record of contribution amounts and dates. The 2026 contribution limit is $4,400 for self-only coverage and $8,750 for family coverage.13Internal Revenue Service. Notice 26-05, HSA Inflation Adjusted Items
Digital Asset Records
Every individual return must answer a yes-or-no question about digital asset activity. If you received cryptocurrency as payment, mined or staked tokens, sold digital assets, or traded one cryptocurrency for another, you must answer “Yes” and report the transactions, even at a loss.14Internal Revenue Service. Digital Assets
Starting with 2025, brokers began issuing Form 1099-DA to report gross proceeds from digital asset sales, similar to a 1099-B for stocks.15Internal Revenue Service. Understanding Your Form 1099-DA Bring that form if you received one. Many decentralized platforms still don’t issue tax forms, so your accountant will also need your own transaction records. For each sale or exchange, document the asset, the date, the number of units, the fair market value in U.S. dollars at the time, and your cost basis. Capital gains go on Form 8949; income from mining or staking goes on Schedule 1.
Deduction and Credit Records
Before you spend hours gathering deduction records, check whether you’ll clear the standard deduction. For 2026, it’s $16,100 for single filers, $32,200 for married couples filing jointly, and $24,150 for heads of household.16Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Itemizing only helps if your total deductible expenses exceed those amounts. A few benefits like the student loan interest deduction and the educator expense deduction are available even if you take the standard deduction, so keep those records either way.
Homeownership
Provide Form 1098 from your mortgage lender, which shows mortgage interest paid, points paid on a new loan, and mortgage insurance premiums.17Internal Revenue Service. Instructions for Form 1098 (Rev. December 2026) Add records of property taxes paid. The state and local tax (SALT) deduction, which combines property taxes, state income taxes, and local taxes, is capped at $40,400 for most filers in 2026 ($20,200 if married filing separately).18Internal Revenue Service. 2025 Instructions for Schedule A (Form 1040) – Itemized Deductions
Charitable Contributions
For any single cash donation of $250 or more, you need a written acknowledgment from the charity stating the amount and whether you received anything in return. Without that letter, the deduction is disallowed no matter how generous the gift.19Internal Revenue Service. Publication 526 (2025), Charitable Contributions For cash donations of any amount, keep bank statements, canceled checks, or credit card statements showing the charity’s name, the date, and the payment.20Internal Revenue Service. Substantiating Charitable Contributions For donated goods, record the fair market value and a description of what you gave.
Medical Expenses
Medical expenses are deductible only to the extent they exceed 7.5% of adjusted gross income, which most people don’t clear.21Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses If you might, give your accountant a full tally of unreimbursed costs for doctor visits, prescriptions, dental work, vision care, and health insurance premiums paid out of pocket. Amounts covered by insurance or paid from an HSA don’t count.
Education
Form 1098-T from your school reports tuition payments; Form 1098-E from your student loan servicer reports interest paid.22Internal Revenue Service. Instructions for Forms 1098-E and 1098-T (2025) The tuition form lets your accountant evaluate education credits like the American Opportunity Credit and Lifetime Learning Credit, which reduce your tax bill directly.23Internal Revenue Service. About Form 1098-T, Tuition Statement The student loan interest deduction is available up to $2,500 a year even if you don’t itemize.
Educator Expenses
Eligible educators who buy classroom supplies with their own money can deduct up to $300 of unreimbursed expenses (combined $600 if both spouses on a joint return qualify). Qualifying purchases include books, supplies, computer equipment, and supplementary materials used in the classroom.24Internal Revenue Service. Topic No. 458, Educator Expense Deduction Keep receipts organized by date and store.
Self-Employment and Independent Contractor Records
Self-employed clients hand their accountants the biggest stack of paper, and this is usually where the meter runs longest. Come prepared and you save yourself the fees that come with disorganization.
Form 1099-NEC reports payments of $600 or more from clients. Clients are required to issue them, but you’re responsible for reporting all self-employment income even if no form was sent. Payment processors like PayPal, Venmo, and credit card companies issue Form 1099-K when gross payments for goods or services exceed $20,000 across more than 200 transactions.25Internal Revenue Service. IRS Issues FAQs on Form 1099-K Threshold Under the One Big Beautiful Bill These forms show gross receipts, so bring them alongside your own bookkeeping records to reconcile the numbers.
Organize expense records by category: office supplies, software subscriptions, professional services, advertising, insurance, and equipment. Large equipment purchases may be depreciated over several years or deducted immediately under Section 179, so note the purchase date and cost for each item. Handing the accountant a summary is far cheaper than handing over a year of bank statements to sort through.
The home office deduction requires either the square footage of your dedicated workspace compared to total home size (regular method) or just the square footage alone (simplified method).26Internal Revenue Service. Office in the Home Frequently Asked Questions The space must be used regularly and exclusively for business. Provide the month and year you started using it, and for the regular method, your home’s adjusted basis and annual expenses (utilities, insurance, rent).
For vehicle expenses, the strongest record is a contemporaneous mileage log with date, destination, business purpose, and miles driven for each trip. The 2026 standard mileage rate is 72.5 cents per mile.27Internal Revenue Service. Notice 26-10, 2026 Standard Mileage Rates To deduct actual expenses instead (gas, maintenance, insurance, depreciation), keep those receipts along with total miles and business miles. Without adequate records the IRS can disallow the deduction entirely, and accuracy-related penalties add 20% to any resulting underpayment.28Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments
Foreign Accounts
If you hold money or investments outside the United States, tell your accountant, even if the accounts produced no taxable income. Two separate reporting requirements can apply, with steep penalties for either.
The FBAR (FinCEN Form 114) is required if the combined value of all your foreign financial accounts exceeded $10,000 at any point during the year. It’s filed with the Financial Crimes Enforcement Network.29Financial Crimes Enforcement Network. Report Foreign Bank and Financial Accounts The penalty for a non-willful failure can reach $10,000 per violation; willful violations carry penalties of the greater of $100,000 or 50% of the account balance.
Form 8938 goes to the IRS with your tax return. For unmarried taxpayers living in the U.S., the threshold is foreign assets over $50,000 on the last day of the year or $75,000 at any time during the year. For married couples filing jointly, it’s $100,000 and $150,000.30Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets? Failing to file carries a $10,000 penalty, rising to $50,000 if you don’t comply after IRS notification, plus a 40% penalty on any underpaid tax attributable to the unreported assets.31Internal Revenue Service. FATCA Information for Individuals
Estimated Tax Payments
If you made quarterly estimated payments, bring the date and amount of each one. Your accountant needs the payment history to calculate whether you still owe or are due a refund, and to determine any underpayment penalty. This most commonly applies to self-employed people, landlords, and anyone with significant income not subject to withholding.
The four quarterly deadlines fall on April 15, June 15, September 15, and January 15 of the following year.32Internal Revenue Service. Estimated Tax – Individuals Safe harbors avoid the underpayment penalty: paying at least 90% of the current year’s tax, or 100% of the prior year’s tax (110% if prior-year AGI was above $150,000). No penalty applies if you owe less than $1,000 after withholding and credits.33Office of the Law Revision Counsel. 26 USC 6654 – Failure by Individual to Pay Estimated Income Tax
If You’ll Miss the Deadline
The federal filing deadline for most individual returns is April 15.34Internal Revenue Service. When to File Filing Form 4868 by that date gives you an automatic six-month extension to October 15.35Internal Revenue Service. Application for Automatic Extension of Time To File U.S. Individual Income Tax Return The extension buys time to file, not to pay. If you owe and don’t pay by April 15, interest and late-payment penalties accrue even with the extension.
The late-filing penalty is worse: 5% of unpaid tax per month, up to 25%.1Internal Revenue Service. Failure to File Penalty If you’re going to miss the deadline and may owe, filing the extension and paying an estimate is far cheaper than filing late. Tell your accountant early so they can help you estimate what you owe and get the extension in.
How to Hand It All Over
Most accounting firms use encrypted client portals for uploading tax documents, which is the safest way to move Social Security numbers and bank details. If your accountant doesn’t offer a portal, ask about their security practices before emailing anything. Dropping off organized paper folders is still common and fine for local practices.
Once the accountant has your documents, expect a follow-up about anything missing or unclear. Responding quickly is the single biggest factor in whether your return gets filed on time. Accountants juggle hundreds of returns during busy season, and files that stall over missing information get pushed to the back of the line.