Once you receive a Social Security number, the IRS says to use it for tax purposes and stop using your ITIN. You must notify the IRS so earlier ITIN records can be combined under the SSN. Updating payroll alone does not complete that IRS record-combination step.
Separate the three updates
| Record holder | What to address |
|---|---|
| IRS | Request that prior ITIN tax records be associated with the new SSN. |
| Employer or payroll provider | Update your legal name and SSN and check future wage reporting. |
| Banks, brokers and other payers | Follow each institution's identification-update process for future information returns. |
Do not file two returns for the same person using different numbers. An ITIN and SSN are not alternative identities to choose between. Preserve the history so payments, withholding and prior returns can be traced correctly.
Prepare the IRS notification
The IRS permits notification at a local IRS office or by a written request explaining that an SSN has been assigned and asking to combine tax records. Its guidance calls for your complete name, mailing address, ITIN, a copy of the Social Security card and a copy of the ITIN assignment notice, CP565, if available.
Check the current address on the official IRS additional-ITIN-information page before mailing. Send copies requested by that guidance, keep the original card safe and retain your letter and delivery record. Use a secure process; do not post either number in a public message or send it through this website's unconnected form.
- Confirm that the SSN has actually been issued, rather than merely applied for.
- Check the name on the card against tax and payroll records.
- Submit the IRS record-combination request using the current instructions.
- Update relevant payers and keep confirmation of the changes.
- Review later transcripts, notices and payment records for mismatches that still need follow-up.
Do old returns need amendments?
Do not amend every prior return solely because an SSN was issued. The IRS record-combination process is distinct from correcting an inaccurate return. If a past return has a substantive error, missing income or a credit issue, review that year separately and check amendment and refund deadlines.
Keep this transition file
- The issued SSN card and any legal-name-change records.
- ITIN assignment notice, previous returns and IRS correspondence.
- Copies of the combination request and proof of delivery.
- W-2s, payment confirmations and employer update correspondence.
ITIN-to-SSN questions
Can I keep using my ITIN because my old refund used it?
The IRS says to discontinue the ITIN once an SSN is received and request combination of the records. Address a pending refund through that documented history.
Does the employer notify the IRS for me?
Updating payroll does not replace your responsibility to notify the IRS about combining ITIN records.
Does an SSN automatically create old-year credit eligibility?
No. Credits have tax-year-specific identification and timing requirements. Review each year rather than assuming the new number changes every past result.
What if an IRS notice still shows the ITIN?
Keep the notice and your notification evidence. Check the account issue and respond by any applicable deadline instead of ignoring it during the transition.
Official sources
Sources checked October 19, 2026. General information; application depends on the tax year and your circumstances.
Your next step
Call to discuss your situation and confirm the documents needed. (323) 364-5589