How many columns does the 1099-NEC IRIS CSV have?

54 in the tax year 2025 formatting guidelines, lettered A to BB.

Can I build the CSV header row myself from this list?

No. Publication 5717 says only CSV templates provided by the IRS can be used. Download the blank template from the portal and fill that.

1099-NEC IRIS CSV columns, A to BB

The tax year 2025 1099-NEC template has 54 columns. This is each one, in order, with its rule.

IRIS is the IRS's free portal for e-filing 1099s. Its CSV upload takes one row per form, in a template you download after signing in. Fields marked * are required. A TIN is a taxpayer identification number: an SSN or an EIN.

Col	Field	Max	Rule
A	Form Type		Example value "1099-NEC".
B	Tax Year		Example value "2025". Each file holds one tax year.
C	Payer TIN Type *		"SSN" or "EIN".
D	Payer Taxpayer ID Number *		Digits and dashes only. EIN as XX-XXXXXXX, SSN as XXX-XX-XXXX.
E	Payer Name Type *		"B" for business name or "I" for individual.
F	Payer Business or Entity Name Line 1	40	Required if name type is B. Letters, numbers, spaces, hyphen, pound, parentheses, ampersand, apostrophe.
G	Payer Business or Entity Name Line 2	40	Same characters as line 1 plus slash and percent.
H	Payer First Name	20	Required if name type is I or a last name is given. Letters, spaces and hyphens.
I	Payer Middle Name	20	Letters, spaces and hyphens.
J	Payer Last Name (Surname)	20	Required if name type is I or a first name is given. Letters, spaces and hyphens.
K	Payer Suffix	20	Letters, spaces and hyphens.
L	Payer Country *		Country abbreviation from the IRS country code list, for example US.
M	Payer Address Line 1 *	35	Letters, numbers, hyphen, slash and space only.
N	Payer Address Line 2	35	Letters, numbers, hyphen, slash and space only.
O	Payer City/Town *	40	Letters and spaces only.
P	Payer State/Province/Territory *		Domestic: 2-letter abbreviation. Foreign: up to 17 letters, numbers and spaces.
Q	Payer ZIP/Postal Code *		Domestic: exactly 5, 9 or 12 digits, digits only. Foreign: up to 9 letters and numbers.
R	Payer Phone Type		"D" for domestic or "I" for international.
S	Payer Phone		Domestic: 1231231234, 123-123-1234 or (123) 123-1234. International: 15 digits or fewer, may start with +.
T	Recipient TIN Type		Required if a TIN is entered. "SSN", "EIN", "ATIN", "ITIN", "QI-EIN" or "UND".
U	Recipient Taxpayer ID Number		EIN and QI-EIN as XX-XXXXXXX. SSN, ITIN and ATIN as XXX-XX-XXXX. UND as XXXXXXXXX.
V	Recipient Name Type *		"B" for business name or "I" for individual.
W	Recipient Business or Entity Name Line 1	40	Required if name type is B. Letters, numbers, spaces, hyphen, pound, parentheses, ampersand, apostrophe.
X	Recipient Business or Entity Name Line 2	40	Same characters as line 1 plus slash and percent.
Y	Recipient First Name	20	Required if name type is I or a last name is given. Letters, spaces and hyphens.
Z	Recipient Middle Name	20	Letters, spaces and hyphens.
AA	Recipient Last Name (Surname)	20	Required if name type is I or a first name is given. Letters, spaces and hyphens.
AB	Recipient Suffix	20	Letters, spaces and hyphens.
AC	Recipient Country *		Country abbreviation from the IRS country code list, for example US.
AD	Recipient Address Line 1 *	35	Letters, numbers, hyphen, slash and space only.
AE	Recipient Address Line 2	35	Letters, numbers, hyphen, slash and space only.
AF	Recipient City/Town *	40	Letters and spaces only.
AG	Recipient State/Province/Territory *		Domestic: 2-letter abbreviation. Foreign: up to 17 letters, numbers and spaces.
AH	Recipient ZIP/Postal Code *		Domestic: exactly 5, 9 or 12 digits, digits only. Foreign: up to 9 letters and numbers.
AI	Office Code		Exactly 4 digits.
AJ	Form Account Number	20	May not equal the payer or recipient TIN.
AK	2nd TIN Notice		"Y" for checked or "N" for unchecked.
AL	Box 1 - Nonemployee Compensation		Box 1 must be filled in or Box 2 checked. 0 to 999,999,999,999,999, not negative, digits with at most one decimal point and two decimal places.
AM	Box 2 - Payer made direct sales totaling $5,000 or more of consumer products to a recipient for resale		"Y" or "N". Box 1 must be filled in or Box 2 checked.
AN	Box 3 - Excess golden parachute payments		Money amount, same rules as Box 1.
AO	Box 4 - Federal income tax withheld		Money amount, same rules as Box 1.
AP	Combined Federal/State Filing (CF/SF) Check all states that apply.		State abbreviations separated by commas and wrapped in quotation marks, for example "AL,CA,DE". No duplicates.
AQ	State 1		Required if any State 1 field is filled in. 2-letter abbreviation.
AR	State 1 - State Tax Withheld		Money amount. One or more payment amounts must be entered if State 1 is selected.
AS	State 1 - State/Payer state number	24	Up to 24 letters and numbers, no spaces or special characters.
AT	State 1 - State income		Money amount, same rules as Box 1.
AU	State 1 - Local income tax withheld		Money amount, same rules as Box 1.
AV	State 1 - Special Data Entries	60	Up to 60 characters.
AW	State 2		Required if any State 2 field is filled in. 2-letter abbreviation.
AX	State 2 - State Tax Withheld		Money amount. One or more payment amounts must be entered if State 2 is selected.
AY	State 2 - State/Payer state number	24	Up to 24 letters and numbers, no spaces or special characters.
AZ	State 2 - State income		Money amount, same rules as Box 1.
BA	State 2 - Local income tax withheld		Money amount, same rules as Box 1.
BB	State 2 - Special Data Entries	60	Up to 60 characters.

Columns A to S describe the payer (you). T to AH describe the recipient. AI to AP hold the account number, check boxes and money boxes. AQ to BB are two optional state sections.

What changes for tax year 2026

The December 2026 form instructions add boxes 1b, 1c and 1d to Form 1099-NEC (cash tips, Treasury Tipped Occupation Code, overtime compensation) and call the compensation box 1a. Expect the 2026 template to have columns this table does not show. Perfrow reads the header row from your own template, so new columns stay in place; it tells you which ones it does not know.

Rules here follow the tax year 2025 guidelines, the newest the IRS has published as of 10 November 2026. Tax year 2026 guidelines were not posted yet. The IRS says the copy inside the Taxpayer Portal is the current one, so check it there before you file.

Fix the whole file at once

Drop in your blank IRIS template and your spreadsheet. Perfrow cleans every row, tells you which ones need you, and writes CSVs of at most 250 records. It runs in your browser, so names and TINs stay on your computer.

Open the 1099-NEC CSV fixer

Questions

How many columns does the 1099-NEC IRIS CSV have?: 54 in the tax year 2025 formatting guidelines, lettered A to BB.
Can I build the CSV header row myself from this list?: No. Publication 5717 says only CSV templates provided by the IRS can be used. Download the blank template from the portal and fill that.

Sources (fetched 2026-11-10)

Other answers: Required fields · Character limits · State codes · 250-record limit · Why files get rejected · Scientific notation · ZIP code format · Date format · Line breaks · Extra spaces · Periods and # · $0.00 cells · Y/N check boxes · Tax year · Error types · Headers do not match · From QuickBooks · TIN format · Key dates