First determine whether you lost the EIN, need proof of it, or have an IRS account that requires updating. An EIN becomes the entity’s permanent federal taxpayer identification number. A dormant business, a bank verification problem, and an IRS account reactivation are not the same issue. [1][2]
Does an EIN expire when the business stops operating?
The IRS says it cannot cancel an assigned EIN, although it can deactivate it. The number remains the entity’s permanent identifier. If the business resumes, establish which account information or filing requirements need attention rather than assuming the number disappeared. [1]
Collect the legal entity name, old assignment notice if available, prior returns, any closing correspondence, and a timeline of the pause and restart. Note any ownership or legal-structure changes separately.
If you only lost the number
Look for the assignment notice, past business returns, bank records, or licensing records. If you still cannot locate the EIN, an authorized person can contact the IRS business line for verification. The IRS may provide the number after verifying identity and authority. [2]
For written confirmation, the IRS describes an entity transcript, a downloadable EIN verification notice for eligible Business Tax Account users, and Letter 147C. Check which option is available for your entity and purpose. Requesting proof is different from obtaining a new number. [2]
Our IRS Business and Specialty Tax Line guide explains the official telephone number and account types handled.
If the IRS says the account needs reactivation
The Internal Revenue Manual describes reactivation procedures for certain previously assigned EIN accounts, including historical accounts dropped from the master file. IRS employees research whether the number belongs to the entity and use internal procedures when reactivation is appropriate. These internal steps are not a public self-service form or a universal online reactivation button. [3]
Describe what happened rather than requesting a particular internal transaction. Ask whether the IRS needs to restore an account, update filing requirements, correct the entity name, or resolve a different mismatch. Record the requested documents and follow-up instructions.
When could you need a new EIN instead?
Ownership and legal-structure changes can require a new EIN, depending on the entity type and facts. Merely changing a business name or address generally does not. Use the IRS entity-specific new EIN guidance before applying again. [4]
| Situation | Question to resolve |
|---|---|
| Original notice is missing | How can an authorized person verify the existing number? |
| Bank cannot match the record | Do the legal name and EIN agree with current IRS evidence? |
| Same entity resumes operations | Which IRS account or filing requirement needs updating? |
| Ownership or structure changed | Do the entity-specific rules require a new number? |
Update the records around the EIN
If the business mailing address or responsible party changed, review Form 8822-B. For a nonprofit, confirming the EIN does not establish current exemption or donation deductibility; see nonprofit EIN and status verification.
Keep the confirmation letter and a concise record of what the IRS actually changed. If a professional will handle the matter for you, confirm the necessary representation or information authorization. That leaves a usable record for the next bank, payroll, or tax filing question.
Primary sources
- IRS: If you no longer need your EIN
- IRS: EIN confirmation and missing numbers
- IRS Internal Revenue Manual 21.7.13: Assigning and reactivating EIN accounts
- IRS: When to get a new EIN
Sources checked: October 31, 2026.