Four concepts drive that path: sale proceeds, cost basis, adjustments and holding period. Holding period decides whether a sale is short-term or long-term.
Form 1040 is a U.S. federal return. This guide may help Australian residents or businesses with U.S. brokerage activity or U.S. filing obligations. Any separate Australian reporting must be assessed on its own terms.
Key Takeaways
- Most 1099-B sales go on Form 8949, then Schedule D, then Form 1040.
- Box 1d proceeds are not taxable gain until basis and adjustments are applied.
- Reconcile every statement, including losses, blank basis and wash sales.
- Foreign holdings, digital assets and cross-border issues need current IRS instructions or professional review.
What Is Form 1099-B and What Information Does It Provide?
Form 1099-B is an information return. A broker prepares it to report securities and certain other transactions to you and the IRS. You don't file it yourself. You use it to prepare your return.
For tax year 2025, the IRS Form 1099-B boxes that matter most are:
- 1a: description of the property
- 1b and 1c: date acquired and date sold
- 1d: proceeds
- 1e: cost or other basis (may be blank for noncovered securities)
- 1f: accrued market discount
- 1g: nondeductible wash-sale loss
- Box 5: noncovered security
- Box 12: basis reported to the IRS
Those boxes feed your gain or loss math, but the form is not the final taxable amount. Proceeds are only one side of the calculation. Gain or loss comes from comparing proceeds with adjusted basis.
Hypothetical example: you sell shares for $5,000 (Box 1d). Your basis is $3,800. Your gain is $1,200, not $5,000. Actual results depend on your records, and this isn't personalized tax advice.
Where Do You Report 1099-B on Form 1040?
The standard path: 1099-B to Form 8949 to Schedule D
For 2025, the steps are:
- List each sale, or each qualifying group of sales, on Form 8949.
- Carry the category subtotals to Schedule D.
- Report the net capital gain or loss on Form 1040, line 7a, according to the 2025 Form 1040.
Confirm line numbers for the tax year you're filing.
How to complete Form 8949 from the 1099-B
Enter each 1099-B transaction on Form 8949 as follows:
- Columns (a) through (e): description, date acquired, date sold, proceeds and basis
- Columns (f) and (g): adjustment code and amount, when needed
- Column (h): proceeds minus basis, after adjustments
Short-term and long-term sales go in separate parts. Generally, long-term means held more than one year.
Understanding the Form 8949 checkboxes
| Box | Term | Status | Schedule D line |
|---|---|---|---|
| A | Short | Basis reported to IRS | 1b |
| B | Short | Basis not reported to IRS | 2 |
| C | Short | No 1099-B received | 3 |
| D | Long | Basis reported to IRS | 8b |
| E | Long | Basis not reported to IRS | 9 |
| F | Long | No 1099-B received | 10 |
Each category needs its own Form 8949. Box 12 and Box 5 on the 1099-B tell you which category applies.
When Form 8949 may not be necessary
Some transactions can go straight to Schedule D line 1a or 8a. That path only works when all of the following are true:
- Basis was reported to the IRS
- No adjustments apply
- The gain or loss is not ordinary income
- No disqualifying collectible or Qualified Opportunity Fund issue applies
The Form 8949 instructions set out the exact conditions.
How the result reaches Form 1040
Schedule D combines short-term and long-term results into one net figure for line 7a. Federal tax withheld in Box 4 is a separate item. It goes into the Form 1040 line 25b withholding total, not into the gain calculation.
Keep your 1099-B and brokerage statements. Copy B says "Keep for your records," so you generally don't attach it. Software may instruct otherwise.
How to Report a 1099-B Step by Step
Gather and review all brokerage tax documents
Collect every 1099-B, consolidated statement, trade confirmation and year-end gain/loss report. Make sure they cover the same tax year and accounts.
Match the form to your own records
Compare descriptions, dates, proceeds, basis, fees and account details. Watch for the same trade appearing on two statements.
Classify each transaction correctly
- Split short-term from long-term.
- Identify covered and noncovered securities.
- Decide whether the sale goes on Form 8949 or qualifies for direct Schedule D reporting.
Enter basis and adjustments accurately
Blank basis isn't zero. For noncovered securities, you must substantiate basis yourself.
Common codes:
- B: incorrect basis. For A/D, keep reported basis in (e) and correct in (g). For B/E, enter correct basis in (e).
- W: wash-sale loss, entered as a positive amount in (g)
- T: wrong gain/loss character
- E: selling expenses not reflected on the statement, entered as a negative amount
- O: other adjustments
Calculate, transfer and review the totals
Example: You sell 100 shares for $5,000 on a long-term basis. The 1099-B shows basis of $3,800 and no adjustments.
Form 8949 (Box D) shows a $1,200 gain. That flows to Schedule D line 8b, then into net long-term gain, then to Form 1040 line 7a. If the broker reported wrong basis, use code B.
Complete a final reconciliation before filing
- Compare Form 8949 totals with every 1099-B.
- Confirm wash-sale and basis adjustments are included.
- Look for missing forms.
- Review the final Schedule D amount.
- Keep supporting records after filing.
Common Situations That Change or Complicate Reporting
Noncovered securities
A broker may give you basis information without reporting it to the IRS. Rebuild basis from purchase confirmations, transfer records, corporate actions and inheritance or gift documents. The IRS Publication 550 puts the burden of proving basis on you.
Wash sales and other adjustments
A loss is disallowed if you buy substantially identical securities within 30 days before or after the sale.
IRS example: buy 100 shares for $1,000, sell for $750, repurchase for $800 within 30 days. The $250 loss is disallowed and replacement basis becomes $1,050. Don't copy proceeds and basis without checking the adjustment columns.
Options, futures and other forms
Section 1256 contracts and straddles use Form 6781. Section 1256 gains are generally 40% short-term and 60% long-term. Other capital-asset options use Form 8949.
Retirement accounts, digital assets and form confusion
- Investments inside IRAs and 401(k)s aren't reported like taxable sales, even if a broker issues a 1099-B.
- Capital gain distributions appear on 1099-DIV, not 1099-B.
- Broker reporting of digital-asset proceeds begins for transactions on or after 1 January 2025, generally on Form 1099-DA.
Missing, incorrect or corrected forms
Ask the broker for the missing or corrected form. Report the transactions anyway, using the "no 1099-B received" category (C or F). If corrected information changes a filed return, file Form 1040-X. Form 4852 doesn't substitute for a 1099-B.
Cross-border and professional review
An Australian resident with U.S. brokerage activity may have separate obligations in both countries. Australian residents must declare foreign capital gains in Australian dollars, and a foreign income tax offset may apply.
Residency, treaty rules, FBAR (over $10,000 aggregate) and Form 8938 thresholds can all matter. Nonresidents may file Form 1040-NR instead. Australian residence alone doesn't establish a Form 1040 obligation.
VJM Global provides tax, accounting and advisory support, including U.S. individual return preparation (Forms 1040 and 1040-NR) and cross-border compliance for Australian and other international clients. It doesn't replace individualised advice for your situation.
Frequently Asked Questions
Where do I report a 1099-B on Form 1040?
Transactions go on Form 8949, then Schedule D, and the net result goes to Form 1040 line 7a. Qualifying unadjusted sales may go directly to Schedule D.
How do I report a 1099-B on my tax return?
Check proceeds, basis, dates, holding period and adjustments against your records. Then enter the sales on Form 8949 and summarize them on Schedule D.
Do I need to report Form 1099-B on my tax return?
Yes, reportable sales generally must be reported, even at a loss. You usually keep the form rather than file it.
What does Form 1099-B report and how does it affect my taxes?
It reports broker transaction details used to compute capital gains or losses. Taxable income depends on basis and adjustments, not proceeds alone.
What does "basis not reported to the IRS" mean?
The broker may not have sent basis to the IRS. You're still responsible for determining and reporting accurate basis.
What is the difference between Form 1099-DIV and Form 1099-B?
Form 1099-DIV reports dividends and distributions, including capital gain distributions. Form 1099-B reports proceeds from sales.
