Form 1099-B or 1099-DA data may be incomplete. Cost basis may be missing. Adjustments may be needed. And if you hold investments through an Australian brokerage, your statements probably won't look like a US form at all.
This guide covers who needs Form 8949, when you can skip it, how to complete it, how totals reach Schedule D and Form 1040, and what Australian-based US taxpayers should check. Form and line references below use the 2025 tax year unless stated.
Key Takeaways
- Form 8949 lists the transactions behind the capital gains and losses on Schedule D and Form 1040.
- Your part and box depend on holding period, what the broker reported, and whether basis was reported.
- You may skip it only when basis-reported transactions need no adjustments.
- Foreign brokers, digital assets and currency conversion need extra documentation.
What Is Form 8949 and Who Must File It?
What the form does
Form 8949, Sales and Other Dispositions of Capital Assets, reports the sales and exchanges of capital assets and reconciles broker-reported amounts with what you put on your return. It is not the tax calculation. It holds the detail (proceeds, basis, dates, adjustments); Schedule D summarises the net result.
Who generally files
You need it if you had a reportable disposition and a US filing obligation. Typical triggers include sales of stocks, bonds, mutual funds, ETFs and digital assets. Receiving a brokerage statement is not the test.
US citizens and resident aliens generally stay taxable on worldwide income wherever they live, per Publication 54. That includes Australians with US citizenship or a green card.
When you may skip it
Exception 1 lets you report totals directly on Schedule D lines 1a and 8a, without Form 8949, when all of these hold:
- The transaction was reported on Form 1099-B (or 1099-DA) with basis reported to the IRS.
- No adjustments are needed to basis, character or gain or loss.
- The Ordinary box is unchecked, and no qualified opportunity fund deferral is involved.
A 1099-B alone does not settle the question. Missing basis, errors, or transactions absent from the statement can still require the form.
Short-term versus long-term
Part I covers short-term transactions (held one year or less). Part II covers long-term (held more than one year). The split matters because Schedule D nets each category separately.
What to gather first
For each disposition, collect:
- Asset description
- Acquisition and sale dates
- Proceeds
- Cost or other basis
- Adjustment code and amount
Pull your 1099-B and 1099-DA forms, trade confirmations, purchase and transfer records, and foreign-currency documents where relevant.
How to Complete Form 8949 Step by Step
Reconcile before you enter anything
Match every sale against broker statements and your own records. Look for missing trades, duplicates, wrong acquisition dates and basis mismatches, especially across multiple platforms.
Pick the right part and box
Each box needs its own page. For 2025:
| Information received | Part I (short-term) | Part II (long-term) |
|---|---|---|
| 1099-B, basis reported | A | D |
| 1099-B, basis not reported | B | E |
| No 1099-B or 1099-DA (non-digital) | C | F |
| 1099-DA, basis reported | G | J |
| 1099-DA, basis not reported | H | K |
| Digital asset, no 1099-DA or 1099-B | I | L |
Check the current-year form before filing, because categories change.
Fill in the columns
- (a) Description of property
- (b) Date acquired
- (c) Date sold
- (d) Proceeds
- (e) Cost or other basis
- (f) Adjustment code
- (g) Adjustment amount
- (h) Gain or loss: (d) − (e) + (g)
If basis was reported to the IRS but is wrong, keep the broker's figure in (e) and correct it through (g). If basis wasn't reported, enter the correct basis directly in (e). Missing basis is not zero basis.
Common adjustment codes
- B: incorrect basis reported.
- W: wash-sale loss disallowed (a positive amount in (g)).
- T: wrong short- or long-term classification on the broker form.
- E: selling expenses or option premiums not reflected.
- O: other adjustments.
A wash sale involves buying substantially identical securities within 30 days before or after the loss sale. Support every adjustment with records. Never add one just to land on an expected result.
Summary reporting
With many transactions, you can enter totals per broker instead of each trade:
- Put the broker name and "see attached statement" in column (a)
- Leave (b) and (c) blank
- Use code M in (f)
- Attach a statement with the same columns
"Available upon request" is not enough.
Illustrative example (not personal tax advice)
Suppose you sell shares for US$1,000. The broker reports basis of US$900, but your correct basis is US$100. In Part II, box D:
- (d) Proceeds: US$1,000
- (e) Cost or other basis: US$900 (keep the broker figure)
- (f) Adjustment code: B
- (g) Adjustment amount: +US$800
- (h) Gain or loss: US$900 gain
That amount flows to Schedule D line 8b. This mirrors the IRS instructions example.
How Form 8949 Connects to Schedule D and Form 1040
From transaction to return
Source documents feed Form 8949. Schedule D then summarises short- and long-term results, and that net figure goes to Form 1040. The 1040 summary never replaces the transaction detail.
Moving totals to Schedule D
| Form 8949 box | Schedule D line |
|---|---|
| A or G | 1b |
| B or H | 2 |
| C or I | 3 |
| D or J | 8b |
| E or K | 9 |
| F or L | 10 |
Exception 1 totals go on lines 1a and 8a.
Form 1040 and loss limits
Schedule D line 16 combines your results. A net gain moves to Form 1040 line 7, while interest and dividends go elsewhere (lines 2a/2b and 3a/3b).
A net loss is deductible up to US$3,000 a year (US$1,500 if married filing separately). The excess carries forward and keeps its short- or long-term character. Under Publication 550, a US$7,000 joint loss means a US$3,000 deduction now and US$4,000 carried forward.
Foreign tax is separate
Foreign tax paid isn't a Form 8949 adjustment just because your broker is overseas. Claim it through Form 1116, then Schedule 3, then Form 1040 line 20. Review US and Australian treatment separately.
Special Situations, Common Errors, and Filing Checklist
Australian brokers and currency
Australian broker statements rarely resemble a Form 1099-B. Unreported non-digital sales fall in Form 8949 boxes C or F.
You must report in US dollars. The general IRS rule uses the spot rate when an item is received, paid or accrued, per IRS currency guidance. Keep your rate source and conversion workings. Don't improvise.
US citizens in Australia remain taxable on worldwide income. The 1982 US-Australia treaty and 2001 Protocol generally preserve that result, with double-tax relief under Article 22.
Digital assets
- Brokers report gross proceeds on Form 1099-DA for 2025 transactions, issued in 2026.
- Basis reporting applies to covered assets disposed of from 2026, generally those acquired after 2025 and held in the broker's custody.
- Earlier acquisitions are noncovered, so you supply the basis.
- Rev. Proc. 2024-28 allows wallet-by-wallet allocation of unused pre-2025 basis, with records required and irrevocable allocations.
Don't rely on one exchange's annual summary if you use multiple wallets, transfers or non-US exchanges.
Pre-filing checklist
- No duplicate or omitted transactions
- Correct dates and holding periods
- Basis entered, not left blank
- Adjustment codes backed by records
- Proceeds consistent with broker statements
- Required statements attached where needed
- Form 8949 totals match Schedule D, and Schedule D matches Form 1040
Final Takeaways: Filing Form 8949 With Confidence
Accurate Form 8949 reporting comes down to a few essentials:
- Reconciled records before you file
- The right box for each sale
- Documented basis and the current IRS instructions
Get a professional review when any of these apply:
- Foreign brokerage activity or digital assets
- Many transactions in one year
- Inherited or gifted assets
- Amended returns
- Unclear US-Australian interactions
VJM Global's team includes US-trained CPAs and Indian Chartered Accountants focused on US tax and international accounting. If you're an Australian-based taxpayer with US compliance questions, ask VJM Global about its cross-border support.
Frequently Asked Questions
Who needs to file Form 8949?
Taxpayers with reportable sales or exchanges of capital assets generally do. A narrow exception covers complete, unadjusted transactions reported with basis. Check the current IRS instructions.
Do I need Form 8949 if I received a Form 1099-B?
Not automatically. If basis was reported and nothing needs adjusting, you may report totals on Schedule D. Missing basis, errors or adjustments mean you file it.
What is Form 8949 used for?
It lists each capital asset disposition in detail. The totals then go to Schedule D and ultimately Form 1040.
When do I attach Form 8949 to my tax return?
File it with Schedule D as part of your federal return when required. For e-filing, transactions are reported electronically, or you mail a paper copy with Form 8453 within three business days of acceptance.
What does Form 8949 look like?
It has two parts: Part I for short-term and Part II for long-term. Each has columns (a) to (h) and checkboxes for Boxes A–F. Use the current IRS PDF, as digital-asset categories have changed.
Where do I report capital gains on Form 1040?
They flow through Schedule D to line 7a of the 2025 Form 1040. Verify the line for later years.
