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Last updated September 11, 2026
An Internal Revenue Service Number (IRSN) is a temporary number the IRS uses to process a return or payment that arrived without a taxpayer identification number. It is not an approved Individual Taxpayer Identification Number (ITIN). If you later submit Form W-7, disclose any prior IRSN on lines 6e and 6f instead of treating the application as if the IRS has no earlier record.
This explains a confusing result: the IRS can reject an ITIN application yet continue processing the attached return. Processing the return does not mean the ITIN was issued.
What is the difference between an IRSN and an ITIN?
The Instructions for Form W-7 define an IRSN as a nine-digit number issued when someone files a return or makes a payment without a taxpayer identification number. IRS internal guidance describes it as an internal-processing number.
| Question | IRSN | ITIN |
|---|---|---|
| Why does it exist? | To process a return or payment without a valid TIN | To identify an eligible person who needs a U.S. TIN and cannot get an SSN |
| Does it mean Form W-7 was approved? | No | Yes, when the IRS issues a CP565 assignment notice |
| Where might you find it? | On IRS correspondence about the affected return | On CP565 and later federal tax records |
| What does a later W-7 ask you to do? | Report it on lines 6e and 6f | Report the prior ITIN on lines 6e and 6f, including for renewal |
Why can the IRS process a return after rejecting Form W-7?
Form W-7 and the attached return are separate processing decisions. The IRS CP566 guidance says that after rejection it processes the return without an ITIN. An eligible applicant must reapply and attach a return copy to obtain any refund due.
The IRS Acceptance Agents Guide, Publication 4520, adds that a valid return attached to a rejected W-7 is processed separately under a temporary IRSN. That does not cure the document, eligibility, or application problem behind the rejection.
A CP566 asks for information while the application remains open; a CP567 means it was rejected. Follow the notice rather than assuming an IRSN requires immediate reapplication.
What should you do with the number shown on IRS correspondence?
Use the document and application status to choose the next step.
| What you have | What it means | Next step |
|---|---|---|
| CP565 assigning an ITIN | The application succeeded | Use the ITIN and keep the notice |
| CP566 requesting information | The application is still under review | Reply with the requested material by the notice deadline; do not start a duplicate W-7 |
| CP567 rejecting the application | No ITIN was issued through that application | Confirm eligibility, correct the stated problem, and submit a complete new package if eligible |
| IRS correspondence showing an IRSN | The IRS has a temporary processing record | Keep the correspondence and disclose the IRSN on the next W-7 |
| No number found or prior number unknown | You cannot supply a number you do not know | Answer “No/Don’t know” on line 6e, as the W-7 instructions permit |
The Form W-7 instructions say an IRSN may appear on correspondence about the return. Review that correspondence before preparing a replacement application.
How do you report an IRSN on Form W-7?
On line 6e, check Yes if you ever received an ITIN or IRSN. On line 6f, enter the number and the name under which it was issued. For multiple IRSNs, attach a sheet listing each one and write your name and “Form W-7” at the top. These directions come from the Form W-7 line 6e–6f instructions.
Do not guess. The instructions allow No/Don’t know when you do not know the prior number. For an ITIN renewal, retrieve and include the previously assigned ITIN to avoid processing delays.
What should you check before reapplying for an ITIN?
- Identify the rejection reason in CP567 or the final notice.
- Confirm SSN ineligibility and a current federal tax purpose for an ITIN.
- Keep the processed return; when reapplying under CP567 guidance, mark the return copy as a copy and follow the notice's mailing instructions.
- Find every prior ITIN or IRSN and its assigned name.
- Correct the evidence problem and submit one complete W-7 package.
For broader notice-response steps, see the CP566 and CP567 application-repair guide.
Form5472 Prep can prepare Form W-7 and have permitted identity documents verified by an IRS-authorized Certifying Acceptance Agent so an adult applicant does not mail an original passport. We cannot determine tax liability, guarantee approval or a refund, or repair an IRS account. Review the ITIN application service once you have a valid federal tax reason.
Frequently asked questions
Is an IRSN the same as an ITIN?
No. An IRSN is temporary and internal. An ITIN is assigned after the IRS approves an eligible Form W-7. Processing a return under an IRSN does not approve an ITIN.
Can I reapply for an ITIN after my return received an IRSN?
Yes, if you remain eligible and correct the prior problem. Submit a new application with a return copy when required, and disclose the IRSN and assigned name on lines 6e and 6f.
Where can I find a prior IRSN?
Check IRS correspondence concerning the return filed without an SSN or ITIN. If you cannot locate or identify a prior number, the Form W-7 instructions allow you to select “No/Don’t know” rather than inventing one.
Educational information only; not tax or legal advice. Authorities checked September 11, 2026.