Filing your taxes online is often the fastest and most efficient way to file — but in some cases, you may still need to take extra steps, like mailing in supplemental materials or your state tax return.
Most taxpayers will not have to mail in any forms after e-filing. And if you do, you will usually be notified if any additional documents need to be filled out, printed, and mailed to the IRS or state revenue department.
For example, if your return also contains Form 8453, then you may need to mail in supplemental materials. This form contains a checklist of possible attachments you may need to mail in to the IRS along with this printed form.
Another reason why you might have to mail in forms after e-filing depends on how you’re handling your state tax return. If you opted not to file your state taxes online, but filed your federal taxes, you may have chosen to physically file and submit your state tax return through the mail.
If you have a tax bill, you may also opt to send your payment through the mail, though you could also pay online.