Your broker sent a corrected Form 1099-B after the original — basis updated from zero, proceeds adjusted, or lot detail fixed for RSU shares. You may have already filed, not yet filed, or received a CP2000. You want to know whether to amend, refile, or wait.
Start here
What you need before using this
- Original and corrected for same sale.
- confirmation for sold lot.
- Form 8949 as originally filed if return already submitted.
- Broker supplemental gain/loss report if separate from .
- for year showing wages in Box 1.
Broker correction timing varies by plan administrator. Basis on corrected 1099-B should tie to vest FMV documentation.
Why this happens
Brokers batch initial before supplemental basis data is ready — corrections follow in March or later.
Corrected may show basis equal to per share times shares sold.
Proceeds may also change if broker corrected for fees or wash sale adjustments.
Tax software imports first — corrected form requires delete-and-reimport or manual adjustment.
IRS receives corrected from broker — may trigger CP2000 if original return showed full proceeds as gain.
Corrected form does not amend — wages unchanged.
Multiple corrections possible for active trading accounts — use latest corrected version.
correction box indicates amended broker reporting.
State tax follows federal Schedule D correction after 1040-X if needed.
Supplemental PDF from broker may show basis before formal corrected — save both.
lines on may get separate corrections from open-market sales.
Lot-level detail on correction helps match specific dates to sale.
If corrected basis matches what you already filed manually, no amendment needed.
Compare -amend-return-timing for CP2000 deadline vs waiting for correction.
Pub. 525 and broker plan guides describe basis reporting timelines.
What to check
- Corrected vs original basis and proceeds columns.
- Whether correction matches confirmation .
- Already filed return — does Schedule D match corrected basis?
- Tax software showing original or corrected import.
- CP2000 outstanding — respond by deadline even if correction arrived.
- All lots on corrected form vs only some lots fixed.
- Wash sale Box 1g changes on correction.
- State copy of if state e-file uses broker data.
Filing twice — original and corrected 1099-B both entered as separate sales
What to check in your documents
- Original PDF.
- Corrected PDF marked CORRECTED.
- Broker supplemental gain/loss statement.
- confirmation for sold lot.
- Filed return Schedule D if amendment needed.
Corrected basis before filing deadline
Illustration only, not your tax situation.
Questions people ask
- What is a corrected 1099-B for RSU sales?
- Broker amendment to prior — often fixes $0 basis to basis.
- Already filed with $0 basis — corrected 1099-B now?
- Generally file Form 1040-X with corrected Form 8949 basis — see amend return timing guide.
- Corrected 1099-B change W-2?
- No — wages unchanged. Correction affects Schedule D sale gain only.
- Use supplemental PDF or wait for corrected 1099-B?
- Either can support correct basis on Form 8949 before filing. Corrected is official broker form.
- Tax software imported wrong 1099-B?
- Delete original import and enter corrected or manual 8949 with basis.
- Corrected 1099-B and CP2000 same sale?
- Respond to CP2000 by deadline with corrected basis documentation — may also amend.
- Two corrected 1099-B forms for same account?
- Use latest correction. Keep all versions for records.
- Corrected basis does not match vest confirmation?
- Reconcile to per share. Contact broker with PDF if mismatch.
- Related guides?
- Why zero, adjust , amend return timing, CP2000 zero basis response.
- Which calculator helps?
- adjustment helper and calculator.
When to get help from a tax pro
- Multiple corrected forms with conflicting basis on same lot.
- Already agreed to CP2000 before corrected form arrived.
- Corrected form shows basis but confirmation differs materially.
- State return already filed with wrong basis from original .
Related calculators
Related pages
- Why Is My RSU Cost Basis Zero?
Zero basis on 1099-B usually means the broker did not link your vest wage income — not that tax was skipped.
- How to Adjust RSU Cost Basis
Basis adjustments connect vest wage income to later sales — document FMV from vest records.
- When to Amend Return for RSU Basis
Amend when you have vest basis proof — but do not miss CP2000 deadlines while waiting for corrected broker forms.
- Respond to CP2000 for RSU Zero Basis
CP2000 proposing tax on full RSU proceeds usually means missing basis — respond with vest FMV documentation, not automatic agreement.
- RSU Supplemental Stock Plan Lot Detail Explained
Supplemental lot detail reports often hold the vest price you need when 1099-B basis is wrong.
Sources and notes
Primary tax claims on this page are supported by the official and secondary sources below. Broker and software links describe reporting mechanics — confirm rules against IRS or state guidance.
Broker corrected 1099-B with vest FMV basis; amend if already filed with zero basis.
- About Form 1099-B — Proceeds from Broker and Barter Exchange Transactions
Internal Revenue Service · Official
Broker reporting of sales proceeds and basis; basis on 1099-B may be incomplete for equity-compensation shares.
- Filing taxes for restricted stock, RSUs, or performance awards (tax guide PDF)
Fidelity Stock Plan Services · Brokerage explainer
Explains W-2 vest income, 1099-B with $0 basis, supplemental adjusted cost basis, and Form 8949 reporting.
- About Form 1040-X — Amended U.S. Individual Income Tax Return
Internal Revenue Service · Official
Amended return process and limitation periods.
For learning, not filing
VestingTax.com is not a CPA firm or tax preparer. Grants, employers, and states all differ. Use the cited IRS and state sources above, your own documents, and a qualified tax professional before you make decisions from this guide.