These are errors and rejects every filer can get when sending information returns to IRIS, whether through the free IRIS Taxpayer Portal or through filing software. IRIS reports each one on the acknowledgment by rule number.
Form 1099-B business rules
Besides the rules on this page, IRIS checks the rules every form shares, such as SHAREDIRFORM014 (payee name and TIN); those are on the cross-form error code pages. The IRIS Taxpayer Portal also takes Form 1099-B as a CSV upload, using the IRS template for the form.
In the tax year 2026 rule set: 3 reject, 5 report error and reject over the threshold, 4 report error. A reject stops the submission; a report error is accepted with errors and counts as filed; past an unpublished threshold, report errors reject the submission. The descriptions are our own summaries; your acknowledgment gives the rule number.
| Rule | Severity | What it checks |
|---|---|---|
| F1099B001 | Report error, reject over threshold | Short-term and long-term cannot both be checked. |
| F1099B002 | Report error, reject over threshold | Federal income tax withheld looks too high compared with the income amounts reported on the form. |
| F1099B003 | Report error, reject over threshold | Gross proceeds and net proceeds cannot both be checked. |
| F1099B004_001 | Report error, reject over threshold | A description of the property is required. |
| F1099B005 | Report error, reject over threshold | Collectibles and QOF cannot both be checked. |
| F1099B006_001 | Report error | When profit or loss on closed regulated futures contracts is reported, the sale fields (dates, proceeds, basis, wash sale, barter, Form 8949 code) must be blank and the sale checkboxes left unchecked. |
| F1099B007_001 | Report error | When unrealized profit or loss on open contracts at the end of the prior year is reported, the sale fields must be blank and the sale checkboxes left unchecked. |
| F1099B008_001 | Report error | When unrealized profit or loss on open contracts at the end of the current year is reported, the sale fields must be blank and the sale checkboxes left unchecked. |
| F1099B009_001 | Report error | When aggregate profit or loss on contracts is reported, the sale fields must be blank and the sale checkboxes left unchecked. |
| F1099B023 | Reject | The date acquired cannot be after the end of the tax year. |
| F1099B024 | Reject | The date sold or disposed of must fall within the tax year. |
| F1099B025 | Reject | The date sold cannot be earlier than the date acquired. |
Elements of Form1099BDetail
Each Form 1099-B return is one Form1099BDetail record in a submission of group 1. The table lists its 37 elements in schema order for tax year 2026: whether each is required, and the format IRIS accepts. Element names are the ones the IRS uses in its IRIS ATS examples and Publication 5718; the IRS revises the schema each year. A FIRE filer converting a Pub 1220 file finds the field-by-field mapping in the Pub 1220 to IRIS crosswalk.
| Element | Required | Format |
|---|---|---|
TaxYr | Required | Four-digit year |
RecordId | Required | Whole number, up to 8 digits |
IssuerOfficeCd | Optional | Exactly 4 characters |
CFSFElectionStateCd | Optional | Two-letter state or territory code |
VoidInd | Required | 1 (yes) or 0 (no) |
CorrectedInd | Required | 1 (yes) or 0 (no) |
PrevSubmittedRecRecipientGrp | Optional | Group of elements |
RecipientDetail | Required | Group of elements |
RecipientAccountNum | Optional | Text, up to 30 characters |
SecondTINNoticeInd | Required | 1 (yes) or 0 (no) |
CUSIPNum | Optional | Text, up to 9 characters |
FATCAFilingRequirementInd | Required | 1 (yes) or 0 (no) |
Form8949ApplicableCheckboxCd | Optional | One of: A, B, D, E, X |
PropertyDesc | Optional | Text, up to 100 characters |
AcquiredDt | Optional | Date, YYYY-MM-DD |
SoldOrDisposedDt | Optional | Date, YYYY-MM-DD |
ProceedsAmt | Optional | Amount, up to 2 decimal places |
CostOrOtherBasisAmt | Optional | Amount, zero or more, up to 2 decimal places |
AccruedMarketDiscountAmt | Optional | Amount, zero or more, up to 2 decimal places |
NondeductibleWashSaleLossAmt | Optional | Amount, zero or more, up to 2 decimal places |
ShortTermGainLossInd | Required | 1 (yes) or 0 (no) |
LongTermGainLossInd | Required | 1 (yes) or 0 (no) |
OrdinaryInd | Required | 1 (yes) or 0 (no) |
CollectiblesInd | Required | 1 (yes) or 0 (no) |
QOFInd | Required | 1 (yes) or 0 (no) |
FederalIncomeTaxWithheldAmt | Optional | Amount, zero or more, up to 2 decimal places |
NoncoveredSecurityInd | Required | 1 (yes) or 0 (no) |
GrossProceedsInd | Required | 1 (yes) or 0 (no) |
NetProceedsInd | Required | 1 (yes) or 0 (no) |
LossNotAllowedInd | Required | 1 (yes) or 0 (no) |
TYClosedContractProfitLossAmt | Optional | Amount, up to 2 decimal places |
PriorYrOpenCntrctProfitLossAmt | Optional | Amount, up to 2 decimal places |
CYOpenCntrctProfitLossAmt | Optional | Amount, up to 2 decimal places |
CntrctAggregateProfitLossAmt | Optional | Amount, up to 2 decimal places |
BasisReportedInd | Required | 1 (yes) or 0 (no) |
BarterAmt | Optional | Amount, zero or more, up to 2 decimal places |
StateLocalTaxGrp | Optional, repeats | Group of elements |