Form-by-form notes: FIRE amount codes to IRIS boxes

In a FIRE file, each box is a numbered or lettered "amount code". The code decides which of the 18 payment amount fields holds the value^[9]. The IRIS CSV names the box instead^[6]. Here is the map for the five forms the converter handles.

1099-NEC (FIRE type of return NE)

FIRE amount code / position	IRIS column
Code 1: Nonemployee compensation	Box 1
Code 4: Federal income tax withheld	Box 4
Position 547: Direct sales indicator	Box 2 (Y/N)
Position 544: Second TIN notice	2nd TIN Notice (Y/N)

IRIS rule: Box 1 must be filled in or Box 2 must be checked^[6].

Tax year 2026. The IRS added boxes for 1099-NEC (1b-1d, cash tips and overtime)^[10]. The IRS's posted CSV guidelines are for TY2025^[5], so use the TY2026 template from your portal. For payments made in 2026, the reporting threshold for nonemployee compensation is $2,000^[11].

1099-MISC (type of return A)

FIRE amount code / position	IRIS column
1 Rents	Box 1
2 Royalties	Box 2
3 Other income	Box 3
4 Federal income tax withheld	Box 4
5 Fishing boat proceeds	Box 5
6 Medical and health care payments	Box 6
8 Substitute payments in lieu of dividends or interest	Box 8
A Crop insurance proceeds	Box 9
C Gross proceeds paid to an attorney	Box 10
F Fish purchased for resale	Box 11
D Section 409A deferrals	Box 12
E Section 409A income	Box 15 Nonqualified deferred compensation
Position 547 Direct sales	Box 7 (Y/N)
Position 548 FATCA	FATCA Filing Requirements (Y/N)

Tax year 2026. New boxes 13a, 13b and 14 were added^[10]. The threshold for rents, other income, medical payments, crop insurance, 409A deferrals and NQDC is $2,000. Royalties stay at $10 and attorney gross proceeds at $600^[10].

1099-INT (type of return 6)

FIRE amount code / position	IRIS column
1 Interest income	Box 1
2 Early withdrawal penalty	Box 2
3 Interest on U.S. Savings Bonds and Treasury obligations	Box 3
4 Federal income tax withheld	Box 4
5 Investment expenses	Box 5
6 Foreign tax paid	Box 6
Positions 547-586 Foreign country or U.S. possession	Box 7 (as an IRS country code)
8 Tax-exempt interest	Box 8
9 Specified private activity bond interest	Box 9
A Market discount	Box 10
B Bond premium	Box 11
E Bond premium on Treasury obligations	Box 12
D Bond premium on tax-exempt bond	Box 13
Positions 587-599 CUSIP	Box 14
Position 600 FATCA	FATCA Filing Requirements

IRIS wants Box 7 as a code from the IRS foreign country code list^[12], while FIRE stores the country name^[9]. For example, Germany is GM and the United Kingdom is UK^[12]. The IRIS template also has a Payer's RTN column (exactly 9 digits)^[6], which has no FIRE field.

1099-DIV (type of return 1)

FIRE amount code / position	IRIS column
1 Total ordinary dividends	Box 1a
2 Qualified dividends	Box 1b
3 Total capital gain distribution	Box 2a
6 Unrecaptured Section 1250 gain	Box 2b
7 Section 1202 gain	Box 2c
8 Collectibles (28%) gain	Box 2d
H Section 897 ordinary dividends	Box 2e
J Section 897 capital gain	Box 2f
9 Nondividend distributions	Box 3
A Federal income tax withheld	Box 4
5 Section 199A dividends	Box 5
B Investment expenses	Box 6
C Foreign tax paid	Box 7
Positions 547-586 Foreign country	Box 8 (IRS country code)
D Cash liquidation distributions	Box 9
E Noncash liquidation distributions	Box 10
F Exempt-interest dividends	Box 12
G Specified private activity bond interest dividends	Box 13

1099-R (type of return 9)

1099-R has the most special fields. See the 1099-R page.

Amount codes and positions are from Publication 1220^[9]. Box names are from the IRIS CSV guidelines^[6].

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Sources

IRS pages checked 2026-11-14. Not affiliated with the IRS. Not tax advice.