Bookkeeping for Small Business Tax: What Records the IRS Requires You to Keep

The Legal Requirement

Under §6001 of the Internal Revenue Code and Treas. Reg. §1.6001-1(a), a person subject to income tax must keep permanent books of account or records, including inventories, sufficient to establish the amount of gross income, deductions, credits, and other matters required to be shown on a return.

According to IRS Publication 583, except in a few cases the law does not require any specific kind of records. A business can choose any recordkeeping system suited to it that clearly shows income and expenses. A business with more than one activity should keep a complete and separate set of records for each, and a corporation should keep minutes of board of directors’ meetings.

What to Keep

Books. A summary of business transactions, ordinarily kept in accounting journals and ledgers or bookkeeping software.

Income records. Invoices, sales records, cash register tapes, deposit records, payment processor reports, and information returns received, such as Forms 1099.

Expense records. Receipts, invoices, canceled checks or bank and card statements, and records showing the business purpose of each expense.

Payroll records. Wage, withholding, and payroll tax deposit and filing records.

Asset records. Records of when and how each business asset was acquired, its cost, improvements, depreciation, and its eventual sale or other disposition.

Certain expenses have stricter substantiation rules. For business use of a vehicle, for example, the IRS expects a log recorded at or near the time of each trip showing the date, destination, business purpose, and miles driven. According to IRS Publication 463, amounts that are approximated or estimated cannot be deducted, and a written record, including one kept on a computer, is generally needed. For business meals, a receipt together with a note of who attended and the business purpose is a practical way to support the deduction.

How Long to Keep Records

According to the IRS, records supporting an item on an income tax return should generally be kept until the period of limitations for that return expires. Unless otherwise noted, the periods run from the date the return was filed (a return filed early is treated as filed on its due date):

• 3 years in the ordinary case
• 3 years from filing, or 2 years from payment of the tax if later, when a claim for credit or refund is filed after the return
• 7 years for a claim for a loss from worthless securities or a bad debt deduction
• 6 years if income that should have been reported, and that is more than 25 percent of the gross income shown on the return, was not reported
• Indefinitely if no return was filed or a fraudulent return was filed
• At least 4 years after the date employment tax becomes due or is paid, whichever is later, for employment tax records

Records relating to property should generally be kept until the period of limitations expires for the year in which the property is disposed of, because they are needed to compute depreciation and the gain or loss on sale. Records may need to be kept longer for non-tax reasons, such as lender or insurance requirements. State agencies have their own rules; the California Department of Tax and Fee Administration, for example, requires sales and use tax records to be kept for at least four years.

Electronic Records

Electronic records are acceptable. According to Publication 583, all requirements that apply to paper books and records also apply to electronic storage systems. An electronic storage system must be able to index, store, preserve, retrieve, and reproduce the records, and it must be maintained for as long as the records are material to the administration of the tax law. Revenue Procedure 97-22 sets out the detailed requirements.

Accounting Methods

Under the cash method, income is generally reported when received and expenses are deducted when paid. Under an accrual method, income is generally reported when earned and expenses are deducted when incurred.

Many small businesses can use the cash method. For tax years beginning in 2026, a corporation or partnership meets the gross receipts test of §448(c) if its average annual gross receipts for the prior three tax years do not exceed $32,000,000 (Rev. Proc. 2025-32). C corporations, and partnerships with a C corporation partner, that exceed that threshold generally must use an accrual method. A small business taxpayer that meets the gross receipts test is also not required to keep inventories in the traditional way and can instead account for inventory as non-incidental materials and supplies or follow its financial statement or books and records treatment.

Once a method is adopted, changing it generally requires IRS consent, which is requested on Form 3115.

If Records Are Missing or Incomplete

When records are inadequate, the IRS can determine income using indirect methods described in its Internal Revenue Manual, such as an analysis of bank deposits and cash expenditures or of the source and application of funds. Reconstructed figures can be difficult to rebut without records, which is one of the strongest practical reasons to keep good books.

The Bottom Line

Any system that clearly shows income and expenses can meet the legal requirement, but it must be supported by source documents and kept for the applicable periods. Organized, complete records make returns easier to prepare and examinations easier to resolve.