New Mexico lesson 4 of 6
Get an EIN and register for New Mexico taxes
The EIN identifies your LLC to the IRS and to banks. Most active New Mexico LLCs also need a state Business Tax Identification Number to handle Gross Receipts Tax and, if you have employees, withholding.
Applying for the EIN
Apply for free directly on the IRS website once your Articles of Organization are 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 for the Business Tax Identification Number
New Mexico issues a Business Tax Identification Number (BTIN) through the Taxpayer Access Point (TAP) or on paper Form ACD-31015. This registration is how you set up Gross Receipts Tax reporting, and it is separate from your federal EIN even though it uses the EIN to identify the business.
When Gross Receipts Tax registration matters
If your LLC has receipts sourced to New Mexico, including from services performed for New Mexico customers, you generally need to register for Gross Receipts Tax and file returns even before you owe any tax, since New Mexico taxes most business activity rather than only retail sales of goods. Register before you start invoicing New Mexico customers to avoid filing catch-up returns later.
Key takeaways
- The EIN is free and comes from the IRS.
- The Business Tax Identification Number is a separate state registration handled through TAP.
- Register for Gross Receipts Tax before invoicing if your LLC has New Mexico-sourced receipts.
Official sources
Or let us file your New Mexico LLC for you
Everything above is yours to use for free. If you would rather hand it over, we prepare and file the Articles of Organization, act as your registered agent, and track your ongoing deadlines.
Last reviewed: September 2026 - reviewed by Gullia Filing Legal & Formation Team