How to Fax IRS Documents | Fast Online Alternative | SecurelyFax
The IRS still accepts some paperwork by fax. The clearest example is Form SS-4, the application for an Employer Identification Number: the current instructions list fax as a submission method, and if you include a return fax number on the form, the IRS generally faxes your EIN back within about four business days. You can send IRS documents online without a fax machine by using email, a browser upload, or a phone scan.
When the IRS still accepts faxed paperwork
Fax is method-specific, not universal. Some forms and authorizations can be faxed, while many returns and payments are handled online or by mail. The reliable rule is to follow the instructions printed on the specific form you are sending, because that is where the IRS states the accepted method and the correct destination number. Form SS-4 is the most common faxable example, and its December 2025 instructions still describe the fax process.
What to verify before you fax a tax form
Check four things. First, that the form's own instructions allow fax. Second, the exact destination fax number from those instructions, which can differ by where you are located. Third, whether the form needs a signature, and that you have signed it. Fourth, for SS-4 specifically, that you have entered a return fax number so the IRS can fax your EIN back instead of mailing it. Getting the return number right is what turns a multi-week mail wait into a few days.
Why online fax can be easier than finding a store
Tax paperwork tends to be time-sensitive, and walk-in stores are limited to business hours with per-page pricing. Online fax lets you send the moment the form is ready, including evenings and weekends, and keep a delivery confirmation. That confirmation is the kind of proof people want for anything tax-related.
Send IRS documents online
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Complete and sign the formFill out the form, sign where required, and for SS-4 enter your return fax number.
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Get it onto your deviceSave it as a PDF, or photograph the signed pages with your phone.
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Enter the destination fax number from the instructionsUse the exact number on the form's instructions and check every digit.
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Send and save the confirmationSend the fax and keep the confirmation with your tax records.
SecurelyFax is not affiliated with the IRS and is not a tax authority. It is a way to transmit your completed documents and keep a delivery confirmation. Always rely on the official form instructions for which method and number to use.
Frequently asked questions
Can I fax Form SS-4 to the IRS?
Yes. The current SS-4 instructions list fax as a submission method. Use the destination number in the instructions and include a return fax number so the IRS can fax your EIN back.
How long does an EIN take by fax?
The IRS generally faxes the EIN back within about four business days when a return fax number is provided.
Do I need a fax machine?
No. You can send the form online from email, an upload, or a phone scan.
Which IRS fax number do I use?
Use the number printed on the specific form's instructions, since it can vary by location and form. SecurelyFax does not assign or replace IRS numbers.
Last reviewed: 2026-05-30