On a paper Form 1040, staple your W-2s and any 1099-Rs or W-2Gs that show federal withholding to the front of the return, paperclip your schedules and other forms behind it in attachment-sequence order, and if you’re sending a check with Form 1040-V, leave both loose in the envelope. That’s the whole rule: something different for each of the three kinds of paperwork. Whether to staple or paperclip your tax return isn’t one decision but three, and the IRS is specific about each.1Internal Revenue Service. Instructions for Form 1040 (2025)2Internal Revenue Service. Form 1040-V (2025)
What Attaches to the Front of Form 1040
Your W-2s go on the front. The face of Form 1040 or 1040-SR has a designated area in the upper-left corner for them. If you received a corrected W-2c, attach both the original and the correction. Forms 1099-R and W-2G only need to be attached if federal income tax was withheld.1Internal Revenue Service. Instructions for Form 1040 (2025)
These income documents need to travel with the return so the IRS can match your reported wages and withholding against what your employer or payer reported. Attaching them to the face keeps them in the right place when the return is opened and scanned.
How to Order the Schedules Behind Your Return
Every IRS schedule and form has a small number in the upper-right corner labeled “Attachment Sequence No.” Stack your schedules behind Form 1040 in ascending order by that number. Schedule 1 is 01, Schedule A is 07, Schedule C is 09, and so on.3IRS Courseware – Link & Learn Taxes. Printing and Storing Returns
Use a paperclip, not a staple, to hold the stack together. The IRS runs paper returns through high-speed scanners, and staples in the body of the return can jam the equipment and slow processing. A paperclip holds everything in place and comes off easily on the other end.1Internal Revenue Service. Instructions for Form 1040 (2025)
If you have supporting statements — the extra detail sheets that explain a line item — arrange them in the same order as the schedules they support and place them at the very back of the stack.1Internal Revenue Service. Instructions for Form 1040 (2025) Print everything on standard-size paper. Trimming pages to save postage can throw off the scanners. And don’t include documents the IRS didn’t ask for.
Why the Check and Form 1040-V Stay Loose
If you owe and are paying by check or money order, include Form 1040-V as your payment voucher. But do not staple or otherwise attach the check, the voucher, or the return to each other. All three go in the same envelope, physically separate.2Internal Revenue Service. Form 1040-V (2025)
The reason is practical. Payments are separated from returns early in processing and routed to a different workflow, so anything holding them together has to be removed by hand, and a check that’s stapled to paper can tear.
Make the check or money order payable to “U.S. Treasury” (not “IRS” or “Internal Revenue Service”). On the check itself, write your name and address, a daytime phone number, the tax year the payment covers, the form number such as “1040,” and your Social Security number.4Internal Revenue Service. Pay by Check or Money Order
Quick Check Before You Seal the Envelope
A missing signature is one of the fastest ways to have a return sent back. Both spouses must sign and date a joint return.5IRS.gov. Return Signature – Publication 4012 A paid preparer must also sign in the preparer section and provide a PTIN; skipping that can trigger a penalty on the preparer for each unsigned return.6Office of the Law Revision Counsel. 26 USC 6695
Walk through the stack one last time. W-2s and any withholding 1099-Rs on the front. Schedules paperclipped behind in sequence-number order, supporting statements at the back. Signed and dated. Correct Social Security numbers on every form. Check payable to U.S. Treasury with the right identifying information, and Form 1040-V filled out. Weigh the envelope; a return with several schedules can easily exceed one ounce and need extra postage.
Proving You Mailed It on Time
The mailing address depends on which form you’re filing and which state you live in, and the IRS updates these addresses periodically, so confirm the current one before you send.7Internal Revenue Service. Where to File Paper Tax Returns With or Without a Payment
Under federal law, a return postmarked by the deadline is treated as filed on time even if the IRS receives it later.8Office of the Law Revision Counsel. 26 USC 7502 The postmark is your proof, so use USPS certified or registered mail to get a receipt showing when you sent it.9Taxpayer Advocate Service. Options for Filing a Tax Return
Certain FedEx and UPS services also qualify under the timely-mailing rule: FedEx First Overnight, Priority Overnight, Standard Overnight, and 2 Day, plus UPS Next Day Air (all tiers) and 2nd Day Air. Regular ground shipping from these carriers does not qualify.10Internal Revenue Service. Private Delivery Services (PDS)