Key Takeaways

  • A tax registration number (TRN) is a unique identifier for individuals and businesses for tax reporting and compliance.
  • TRNs vary by jurisdiction and can include SSNs, EINs, ITINs, TANs, and TFNs.
  • Businesses may need federal and state tax IDs to meet all regulatory requirements.
  • Applying for a TRN typically involves IRS or state tax agency forms and may differ based on entity type.
  • Failure to obtain or correctly use a TRN can lead to legal or financial penalties.

What Are the Types of Tax Registration Numbers?

Depending on the type of business you have and other factors, you may need to register for one of the following types of ID numbers for taxation:

  • The tax ID number (TIN) is required on all tax returns filed with the IRS. If you are a sole proprietor, you can use your Social Security Number for this purpose. Social security numbers are the most common type of TINs. These numbers are issued by the Social Security Administration and are typically obtained by parents when a new baby is born so that they can claim the child as a dependent. No cost is associated with an SSN application. Trusts and fiduciaries also use a TIN for financial reporting.
  • If your business has other employees besides yourself, you will be required to register with the IRS for a separate employer ID number (EIN). Businesses can obtain this number for free by completing IRS Form SS-4.
  • A state EIN is used to file your state taxes. In many states, this is the same as your IRS ID number. In other states, you will need to obtain a separate number if you have employees. These states currently include South Carolina, Massachusetts, and New York.
  • An individual tax ID number (ITIN) is assigned to nonresident aliens who may need to report taxes to the IRS. This is used for individuals who are not eligible for an SSN, such as the spouse of an individual who works in the United States. To register for an ITIN, you will need to complete IRS Form W-7 and include supporting documents that indicate your legal working status in the U.S. You can also consult an agency such as a bank, accounting firm, or college for assistance.
  • The adoption tax ID number (ATIN) is used when parents adopt a child domestically but are unable to register for an SSN for the baby before taxes are due. Eligible children must be in the process of being adopted and must be U.S. citizens.
  • The preparer tax ID number (PTIN) is used on returns filed by a professional tax preparer and have become mandatory as of 2011. A professional preparer is defined as anyone who prepares all or part of another individual's tax return in exchange for a fee.

Once you have registered for your tax number, it must be used on all IRS documents and other financial filings.

How to Apply for a Tax Registration Number

To apply for a tax registration number, you'll typically need to determine the appropriate type for your situation—whether it's an SSN, EIN, ITIN, or a state-specific tax ID. The process varies depending on the number:

  • SSN (Social Security Number): Apply through the Social Security Administration (SSA), usually using Form SS-5.
  • EIN (Employer Identification Number): Apply via IRS Form SS-4, which can be completed online for immediate assignment.
  • ITIN (Individual Taxpayer Identification Number): Use IRS Form W-7 along with required identification documents.
  • State Tax ID Number: Most state revenue departments have online portals or applications that mirror the EIN process. Some states assign their own ID distinct from the federal EIN.

After application, you'll receive your number either immediately (EIN), within a few weeks (SSN, ITIN), or per state-specific timelines.

State Tax Registration Numbers Explained

While the IRS issues federal tax numbers like the EIN, many states require a separate state tax registration number for tax reporting, payroll, or sales tax purposes. This number is typically used for:

  • State income tax withholding
  • Sales tax collection and remittance
  • Unemployment insurance contributions
  • Other state-specific tax obligations

For example, in California, a business may need to register with the Franchise Tax Board and the Employment Development Department. In Texas, businesses collect and remit sales tax using a state-issued tax permit number.

Always check with your state’s department of revenue to determine which numbers are necessary.

What Is a Tax Deduction and Collection Account Number?

This number, also called TAN, is a 10-digit alphanumeric code used in India to track those responsible for collecting and deducting taxes on behalf of the Income Tax Department. This includes wages deducted or collected at the source, which must be deposited to the Indian government. Private limited companies, proprietorships, and other business entities must apply this procedure to salaries, contractor or subcontractor payments, and rent payments exceeding a certain amount.

Under the Indian Income Tax Section 203A, TAN must be included in all deduction and collection returns, payments, and certificates that are issued. You will also use this number anytime you need to communicate with India's Income Tax Department and include it on correspondence with your bank or financial institution.

When tax is deducted from an income source, the TAN entity will provide proof of tax collection in the form of a TDS Certificate. Failure to obtain a TAN or use it as required carries a penalty of 10,000 rupees. Businesses can apply for the TAN online.

This number is called a tax file number in Australia. Businesses and employers must apply for this number and will use it permanently once it is assigned.

What Is a Tax Registration Number Used For?

A tax registration number is crucial for ensuring that tax authorities can accurately track your income, tax payments, and filings. It's required for:

  • Filing tax returns
  • Opening business bank accounts
  • Hiring employees (for EIN holders)
  • Communicating with tax agencies
  • Issuing 1099 or W-2 forms

Without a valid TRN, you may face issues with tax compliance, including fines or delayed processing of refunds and filings. Whether you’re a sole proprietor using your SSN or a corporation using an EIN, your TRN becomes the backbone of your tax identity.

International Variants of Tax Registration Numbers

Different countries have their own versions of tax registration numbers:

  • Ireland: Uses the TRN for business tax registration, assigned by Revenue.
  • India: Uses TAN (Tax Deduction and Collection Account Number) for entities deducting tax at source.
  • Australia: Uses the Tax File Number (TFN) for individuals and businesses.

While the function is consistent globally—ensuring tax compliance—the structure, issuing authority, and application processes differ.

Frequently Asked Questions

  1. Do I need a tax registration number if I’m self-employed?
    Yes. If you're self-employed, you’ll typically use your SSN or may need to apply for an EIN depending on the scale of your business.
  2. How do I know which type of TRN I need?
    It depends on your role. Individuals use SSNs or ITINs, while businesses often require EINs and state tax IDs.
  3. Can I have multiple tax registration numbers?
    Yes. For example, a business can have an EIN, a state tax ID, and additional numbers like TAN or TFN if operating internationally.
  4. Is there a fee to apply for a tax registration number?
    Most U.S. federal tax IDs, like the EIN, are free through the IRS. State and international variants may have associated fees.
  5. How long does it take to get a TRN?
    EINs are usually issued immediately if applied online. SSNs, ITINs, and state IDs can take days to weeks, depending on the agency.

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