Hi yall, I get multiple 1099s from my banks for the different taxable accounts, containing summary pages with each the 1a, 1b dividends, 2a capital gains and whatever else bix info to enter in the 1040 and usually also multiple pages of details and blabla. Do I have to provide the full details of the 1099s when paper filing or is the summary page as reference enough as to what is entered in the 1040s? Copies of W2s to be included is mandatory for sure that I know.
Last year my envelopes were pretty bloated.
What supporting documents do I need to attach to filing paperwork of 1040s?
byu/NOKIMI247 intax
Posted by NOKIMI247
6 Comments
No. Generally you only include the forms that comprise the tax return and the W-2s. Everything else goes in your records.
Obligatory question: are you 100% sure you definitely cannot file electronically?
you don’t send 1099’s Why are you doing this manually?
You only need to attach 1099’s if they show federal tax withholding.
Are you filing on paper?
From page 67 of the 2025 Form 1040 instructions:
>Don’t attach correspondence or other
items unless required to do so. Attach
Forms W-2 and 2439 to Form 1040 or
1040-SR. If you received a Form W-2c
(a corrected Form W-2), attach your
original Forms W-2 and any Forms
W-2c. Attach Forms W-2G and 1099-R
to Form 1040 or 1040-SR if tax was
withheld.
https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
You submit only the forms you complete (Form 1040, its schedules, and supporting forms like Form 8949) and a copy of any informational forms which show federal income tax withheld (usually just Form W-2).