An accounting year end is the last day of the twelve-month period a business or individual uses to track income and expenses for tax and financial reporting. For most individuals and many small businesses that date is December 31, but the IRS lets businesses close their books on the last day of another month if a different rhythm fits the operation better. The date matters because it fixes when you stop counting the current year’s activity, when adjusting entries and financial statements are prepared, and when the clock starts on filing your return.
The Three Types of Accounting Year
Federal tax law recognizes three. A calendar year runs January 1 through December 31 and is the default for individuals, sole proprietors who keep no formal books, and any entity that hasn’t elected something else. If you’ve never chosen a fiscal year, the IRS assumes you’re on a calendar year.1Internal Revenue Service. Tax Years
A fiscal year is any twelve consecutive months ending on the last day of a month other than December. A company that closes on June 30, for example, reports all activity from July 1 through the following June 30.2Office of the Law Revision Counsel. 26 USC 441 – Period for Computation of Taxable Income
A 52-53 week year always ends on the same weekday near the end of a chosen month, so some years run 52 weeks and others 53. Retailers use it often. The IRS allows two ways to pin the date: the last time that weekday falls within the calendar month, or the closest occurrence of that weekday to the last day of the month. Under the first, the year can end up to six days before the month’s final day; under the second, up to three days into the next month.3eCFR. 26 CFR 1.441-2 – Election of Taxable Year Consisting of 52-53 Weeks
Who Can Choose a Fiscal Year and Who Cannot
The best year end usually lines up with the natural rhythm of a business rather than the calendar. Retailers commonly close on January 31 so the entire holiday season and the wave of January returns fall inside one reporting period, which also keeps physical inventory counts out of the busiest sales weeks. A ski resort might pick April 30, an agricultural business October 31, a professional services firm a date that dodges its busiest client months.
Not every entity gets that flexibility. Partnerships, S corporations, and personal service corporations generally must use the calendar year unless they can show a valid business purpose for a different period or make an election under Section 444.4Internal Revenue Service. 2025 Instructions for Form 1120-S C corporations have more room but still need to stay with whatever year they adopt unless the IRS approves a change through Form 1128. Some changes qualify for automatic approval; the rest require a ruling and a user fee that ranges from $625 to $5,300 depending on gross income.1Internal Revenue Service. Tax Years Pick the year end carefully at the start, because changing it later is expensive and administratively heavy.
Closing the Books at Year End
Closing the books is a sequence of steps that turns a working ledger into a locked, auditable record. Skip a step or work out of order and you’ll reopen the period to fix errors.
Gather the Records First
Closing goes smoothly when documentation is already in place. Before you start, pull together:
- Bank and credit card statements for the full year, downloaded directly from the institution.
- Payroll records — W-2s, quarterly 941s, and year-end summaries — reconciled against each other and against the general ledger wages account. Employment tax records must be kept for at least four years after the tax is due or paid.5Internal Revenue Service. Employment Tax Recordkeeping
- Inventory counts as of the last day of the year, since the ending inventory figure drives cost of goods sold.
- Accounts receivable and payable aging reports.
- Fixed asset records reconciled to the physical assets, with cost basis, date placed in service, and accumulated depreciation for each.
- Expense receipts organized by category, especially for travel, meals, and equipment purchases.
- For C corporations, ownership percentages, dividend payments, and officer compensation. A separate Form 1125-E is required when total receipts reach $500,000.6Internal Revenue Service. Instructions for Form 1120 (2025)
Reconcile Every Account
Match every bank account, credit card, and loan balance in your accounting software to the corresponding statement as of the last day of the year. Discrepancies usually come from unrecorded fees, deposits in transit, or outstanding checks. Every dollar has to be accounted for before you move on.
Record Adjusting Journal Entries
Adjusting entries bring the books in line with economic reality. The most common ones at year end:
- Depreciation on every fixed asset for the current year.
- Accrued expenses for goods or services received but not yet billed, such as utilities or the last week of December wages.
- Prepaid expenses moved from the asset account into expense for the portion of the year they cover.
- Bad debt write-offs or an adjustment to the allowance for doubtful accounts.
- Accrued revenue for accrual-basis businesses that have earned income but not yet invoiced.
Generate Financial Statements and Close the Temporary Accounts
Once adjusting entries are posted, produce the income statement and balance sheet and review them for anything that looks off: an unexpected spike in a category, a negative balance in an asset account, a receivable that should have been written off. This is the last chance to catch errors before the books are locked.
Then close revenue, expense, and dividend accounts (the temporary accounts) to zero and transfer the net result into retained earnings for corporations or owner’s equity for other entities. Most accounting software automates the entry, but verify that the only accounts still carrying balances afterward are assets, liabilities, and equity. Run a post-closing trial balance to confirm debits equal credits and no temporary account still shows a balance.
Lock the Period
Set a closing date password in the accounting software so no one posts transactions back into the completed year. Any change after this point should require authorization and should be made as a prior-period adjustment in the new year, not by reopening the old one.
Filing Deadlines Set by Your Year End
The year end date is what determines when the return is due. For calendar-year filers:7Internal Revenue Service. Publication 509 (2026), Tax Calendars
- Individuals (Form 1040): April 15. An automatic six-month extension pushes filing to October 15, but estimated taxes are still due April 15.
- Partnerships (Form 1065): March 15, the 15th day of the third month after the tax year ends.
- S corporations (Form 1120-S): March 15.
- C corporations (Form 1120): April 15, the 15th day of the fourth month after the tax year ends.
Fiscal-year filers use the same month-count from their own year end. A C corporation with a June 30 year end files by October 15. Form 7004 grants an automatic six-month extension for most business entity types.8IRS.gov. Form 7004 Due Dates PY2026 The extension covers filing, not payment. Estimated tax is still due by the original date.
1099s and Late-Filing Penalties
Year end is not just about your own return. If you paid an independent contractor, freelancer, or vendor $600 or more during the year, a Form 1099-NEC goes to the recipient and to the IRS by January 31. A 1099-MISC goes to the recipient by January 31 and to the IRS by February 28 on paper or March 31 electronically.9IRS. Publication 1099 General Instructions for Certain Information Returns (For Use in Preparing 2026 Returns)
Penalties for late or incorrect 1099s scale with how late the correction is made: $60 per form within 30 days, $130 through August 1, and $340 after that. Intentional disregard doubles the penalty to $680 per form with no cap.10Internal Revenue Service. Information Return Penalties Collecting W-9 information from contractors before year end avoids the January scramble.
Missing your own filing deadline triggers penalties that depend on entity type. For partnerships and S corporations, the penalty is $255 per partner or shareholder per month (or partial month) up to twelve months. A ten-member LLC taxed as a partnership that files three months late faces $7,650. For individuals and C corporations, the penalty is 5% of the unpaid tax per month, capped at 25%.11Internal Revenue Service. Failure to File Penalty
First-time penalty abatement is worth knowing about. The IRS will waive failure-to-file, failure-to-pay, and failure-to-deposit penalties if you’ve filed the same return type for the prior three years, received no penalties in that period (or had them removed for an acceptable reason), and are otherwise in compliance.12Internal Revenue Service. Administrative Penalty Relief You can request it when you receive the penalty notice.
How Long to Keep the Records
Once the books are closed and the return filed, retention periods depend on the record type:13Internal Revenue Service. How Long Should I Keep Records
- General business records: three years from the filing date, covering the standard audit statute of limitations.
- Employment tax records: four years after the tax is due or paid, whichever is later.5Internal Revenue Service. Employment Tax Recordkeeping
- Unreported income exceeding 25% of gross income: six years.
- Worthless securities or bad debt deductions: seven years.
- Property records: until you dispose of the property, then the applicable period after that year’s return is filed.
- Unfiled or fraudulent returns: indefinitely, because there is no statute of limitations on those.
Most accountants keep everything for at least seven years. Digital storage is cheap, and recreating a missing document during an audit costs far more than keeping a backup.