Check Box F on Form 8949 when you sold a capital asset you held for more than one year and no broker sent you a Form 1099-B for the sale. It sits in Part II of the form and is the box for long-term sales the IRS has no independent record of, which most often means inherited property, private stock sales, or direct real estate transactions handled without a broker. Because nothing was reported to the IRS, you are responsible for the proceeds figure, the cost basis, and the paperwork behind both.
When Box F Is the Right Box
Box F applies to any long-term capital asset sale where no information return was filed. A handful of situations account for almost all of them.
Inherited Property
Selling inherited stocks, real estate, or other assets is the most common Box F situation. When you inherit property, the brokerage or transfer agent holding the asset rarely has the information needed to file a 1099-B for the eventual sale. The basis for inherited property is generally stepped up to the fair market value on the date of the decedent’s death, replacing whatever the original owner paid.1Office of the Law Revision Counsel. 26 US Code 1014 – Basis of Property Acquired From a Decedent Since the broker has no record of that stepped-up value, it does not report basis to the IRS, and in many cases does not file a 1099-B at all.
If the estate’s executor elected the alternative valuation date, the basis is instead the fair market value six months after death, or the date the property was sold or distributed if that happened within the six-month window.2Office of the Law Revision Counsel. 26 USC 2032 – Alternate Valuation Either way, you need an appraisal, an estate valuation report, or a brokerage statement from the relevant date to support the number you put on Form 8949.
Private Sales of Investment Property
Direct sales between individuals with no broker involved produce no 1099-B. Selling shares in a private company to another investor is a Box F transaction if you held those shares for more than a year. The same goes for selling investment land or other property directly, provided the transaction was not reported on a Form 1099-S by a real estate closing agent.3Internal Revenue Service. Instructions for Form 1099-S
A Boundary: Digital Assets Have Their Own Boxes Now
Starting with 2026 tax returns, cryptocurrency and other digital assets can no longer be reported using Boxes A through F. Long-term digital asset sales use new Boxes J, K, and L in Part II, and brokers now issue Form 1099-DA instead of 1099-B.4Internal Revenue Service. Instructions for Form 89495Internal Revenue Service. About Form 1099-DA, Digital Asset Proceeds From Broker Transactions If you sold cryptocurrency held more than a year with no 1099-DA, the correct box is L, not F.
Box F vs Box E: The Most Common Mistake
Box E and Box F both involve missing basis, and taxpayers regularly confuse them. The distinction is simple but important. If you received a 1099-B and the basis field is blank or marked as not reported to the IRS, that is Box E. Box F is reserved for sales with no 1099-B whatsoever.
This matters because of noncovered securities: assets purchased before brokers were required to track and report cost basis (the cutoff was January 1, 2011 for individual stocks, with later dates for mutual funds, bonds, and options).6Internal Revenue Service. Instructions for Form 1099-B When you sell a noncovered security through a brokerage, the broker still files a 1099-B reporting the proceeds; it just leaves the basis field blank. That is a Box E transaction, not Box F.
The practical consequence: the IRS already knows about Box E sales from the broker’s 1099-B, but it knows nothing about Box F sales unless you report them. Putting a Box E sale on Box F (or the reverse) creates a mismatch in the IRS’s automated matching system and can generate a CP2000 notice even when your tax is calculated correctly.
Filling Out Part II, Column by Column
Check Box F at the top of Part II, then work through the eight columns for each transaction.7Internal Revenue Service. Form 8949 – Sales and Other Dispositions of Capital Assets
Column (a) — Description of property. Be specific. For stocks, include the number of shares and the company name. For real estate, use the property address.
Column (b) — Date acquired. The date you originally purchased or received the asset. For inherited property, you can enter “Inherited” or the decedent’s date of death.4Internal Revenue Service. Instructions for Form 8949
Column (c) — Date sold or disposed of. This date must be more than one year after the date in Column (b) for the sale to qualify as long-term. The IRS counts from the day after acquisition through the day of sale.8Internal Revenue Service. Topic No. 409, Capital Gains and Losses
Column (d) — Proceeds. The total amount you received from the sale. For real estate, this comes from the closing statement. For private sales, use the contract price.
Column (e) — Cost or other basis. This is where Box F requires the most work. You calculate the figure yourself using purchase records, appraisals, or estate documents. For inherited property, enter the stepped-up fair market value on the date of death.9Internal Revenue Service. Gifts and Inheritances For real estate you purchased directly, use the original price plus capital improvements and minus any depreciation you claimed or should have claimed.
Column (f) — Adjustment code. If the basis needs an adjustment beyond what you entered in Column (e), enter the code. The most common are “W” for wash sales and “B” for basis corrections.10Internal Revenue Service. Form 8949 Codes Leave blank if no adjustment applies.
Column (g) — Amount of adjustment. The dollar amount of the adjustment from Column (f). A positive number increases your gain; a negative number (in parentheses) decreases it. Leave blank if Column (f) is blank.
Column (h) — Gain or loss. Column (d) minus Column (e), plus or minus Column (g). A positive number is a gain; a negative number is a loss. This figure flows to Schedule D.
Figuring Basis When Records Are Thin
Box F transactions tend to involve older assets or inheritances where documentation has gone missing. This is the weakest point in most Box F filings and the spot where audits focus.
For inherited property, start with the estate’s tax records. If a Form 706 estate tax return was filed, it contains appraised values for the decedent’s assets. If no estate return was filed, look for brokerage statements from the date of death showing closing prices, or get a retroactive appraisal for real estate. Historical stock prices from financial data services can serve as evidence of fair market value.
For assets you purchased years ago without a broker, search for cancelled checks, bank statements, settlement documents, and correspondence from the time of purchase. If you made capital improvements over the years, gather those receipts too, since improvements increase your basis and reduce the taxable gain.
When exact records are unavailable, tax courts have recognized what is known as the Cohan rule, which allows taxpayers to rely on reasonable estimates of basis as long as there is some factual foundation for the estimate. Courts have noted that perfect precision is “usually impossible and unnecessary.” The rule gives less favorable treatment when the missing records are your own fault, and the IRS can reject estimates that look like guesswork. Reconstruct what you can from secondary sources before resorting to estimation.
Where the Totals Go
After completing all Box F entries, total Columns (d), (e), (g), and (h). Those totals transfer to Line 10 of Schedule D (Form 1040).7Internal Revenue Service. Form 8949 – Sales and Other Dispositions of Capital Assets If you also have transactions under Boxes D or E, each category needs its own copy of Form 8949, and each flows to its own line on Schedule D.
Form 8949 must be filed with Schedule D as part of your return; e-filing software transmits it automatically. The aggregate gain or loss on Schedule D then factors into your total tax on Form 1040.4Internal Revenue Service. Instructions for Form 8949
Long-term gains reported through Box F qualify for the preferential long-term rates: 0%, 15%, or 20% for 2026 depending on your taxable income and filing status.8Internal Revenue Service. Topic No. 409, Capital Gains and Losses High-income taxpayers may also owe the 3.8% net investment income tax on top of those rates.
Penalties When the Basis Won’t Hold Up
Because Box F sales carry no broker-reported basis for the IRS to cross-check, errors are both more common here and harder for the IRS to catch immediately. That does not mean they go unnoticed forever. Audits of inherited property sales are a routine IRS examination target.
If the IRS finds that you underreported a gain by using an inflated basis, you owe the additional tax plus interest. For the second quarter of 2026, the IRS charges 6% annual interest on individual underpayments, compounding daily.11Internal Revenue Service. Internal Revenue Bulletin 2026-08
On top of interest, the IRS can impose a 20% accuracy-related penalty on the portion of your underpayment caused by negligence or a substantial understatement.12Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments Reporting a basis you cannot substantiate is exactly the kind of error that lands in this category. Documentation is the defense, not estimation.
How Long to Keep the Records
The general rule for tax records is three years from the filing date, but capital asset records work differently. Keep records that support your basis until the period of limitations expires for the year you sell or dispose of the property.13Internal Revenue Service. Topic No. 305, Recordkeeping If you buy an asset in 2005 and sell it in 2026, you need the original purchase documentation through at least 2029, and longer if you underreport income by more than 25%, which extends the period to six years.14Internal Revenue Service. How Long Should I Keep Records
For inherited assets, keep the estate valuation documents, appraisals, and any correspondence with the executor for the same period. Digitize paper records where you can. Losing your basis documentation for a Box F transaction effectively means you cannot defend the most important number on the form.