The Internal Revenue Service provides instructions for assembling your tax return, including what to do with your W-2s and where to send the forms if you e-filed your return. These instructions describe where to place any required supporting documents for your return, and how to organize them. Instructions for e-filers differ from those for taxpayers who mail their returns.
Attachments to the 1040 Form
Taxpayers who mail in their tax returns attach their W-2s to the front of the individual tax return form used. Look for the instruction, "attach W-2 forms here," in the middle of the page at the left margin. The IRS also directs taxpayers to attach, if received, any 1099-R, Form W-2c and Form 2439. E-filers do not send W-2 forms to the IRS; however, they should use the appropriate form to mail other required documents to the agency.
Mailed Tax Returns
Assemble other forms and documents behind the 1040 form in the required order if you're mailing in your form. The IRS instructs taxpayers to include only those forms and documents that are required or requested. Assemble the forms and schedules first behind the 1040 form. Place them in order using the "Attachment Sequence No." listed on the form or schedule. Place supporting statements together behind all of the forms and schedule. Use the same order for supporting statements as used for the related forms and schedule. Read the Form 1040 instruction booklet for current tax return assembly rules.
E-filed Tax Returns
E-filers use Form 8453 to mail specific attachments to the IRS. Send only those forms and documents included in the checklist on Form 8453. Taxpayers may not use this form to submit payments or to send Forms 2439, 1099-R, W-2, W-2c or W-2G. Mail the form and attachments to the address provided on Form 8453.
Payments
Taxpayers who file by mail include payment with their paper tax return or make payment electronically using the IRS website. To pay by mail, use Form 1040-V and mail it in by the April 15 deadline unless other payment arrangements have been made. Taxpayers who e-file and choose not to submit payment electronically also use Form 1040-V to mail payments to the IRS. Do not use stables or paper clips to attach the check or money order to the payment voucher or to attach the payment voucher to the tax return form. You may enclose the payment voucher and payment in the envelope with your tax return.
State Tax Forms
Your state tax department also includes instructions for assembling tax returns, including placement of attachments, when filing your state tax return. Visit your state's tax department website or locate the assembly instructions on your state's tax forms for the details.