Idaho lesson 4 of 6
Get an EIN and register with the Idaho State Tax Commission
The EIN identifies your LLC to the IRS and to banks. Idaho routes most state tax registrations, including sales tax permits and withholding accounts, through a single Idaho Business Registration process.
Applying for the EIN
Apply for free directly on the IRS website once your Certificate of Organization is approved. If the responsible party has a US social security number or ITIN, the EIN is issued immediately online; otherwise the application goes in on Form SS-4 by fax or post.
Registering with the Idaho State Tax Commission
You must have your EIN before registering for an Idaho withholding account. Use the Idaho Business Registration (IBR) process, available online or on paper Form IBR-1, to apply for a seller's permit if you sell taxable goods or certain services, and for a withholding account if you have employees. The same IBR process also covers Idaho Department of Labor unemployment insurance and Idaho Industrial Commission registrations for employers.
When a seller's permit is required
You generally need a regular seller's permit if you make taxable sales of goods or services in Idaho, sell outside of a registered marketplace facilitator that already collects Idaho tax on your behalf, and do not qualify for an exemption such as the occasional sale exemption. Check the Tax Commission's current guidance on which sales require a permit before you start selling.
Key takeaways
- The EIN is free and comes from the IRS, and you need it before applying for an Idaho withholding account.
- Idaho Business Registration (IBR) is the single process for seller's permits, withholding, and employer registrations.
- Confirm whether your specific sales require a seller's permit before you start invoicing customers.
Official sources
Or let us file your Idaho LLC for you
Everything above is yours to use for free. If you would rather hand it over, we prepare and file the Certificate of Organization, act as your registered agent, and track your ongoing deadlines.
Last reviewed: September 2026 - reviewed by Gullia Filing Legal & Formation Team