A Taxpayer Identification Number (TIN) is more than just a random string of digits—it’s a unique key for all individuals and businesses within the United States tax system. Issued by either the Internal Revenue Service (IRS) or the Social Security Administration (SSA), these numbers ensure that income tax returns, federal tax filings, and other tax-related activities are accurately tracked and processed.
What are the types of TINs?
There are five main types of TINs—each one serves its own purpose. Whether you’re an individual filing your first tax return or a business owner managing employees and finances, having the correct TIN is essential for compliance and efficiency.
What is a Social Security Number?
A Social Security Number (SSN) is a nine-digit identifier used by U.S. citizens and eligible residents. Issued by the government, they are used for tracking lifetime earnings and years worked, calculating benefits like disability income, and identifying people for tax purposes and credit reports.
What is an Employer Identification Number?
An Employer Identification Number (EIN) is a federal tax identification number. It is a nine-digit number unique to each business and assigned by the Internal Revenue Service (IRS) to those that require one. Acquiring an EIN is required to hire and pay employees, open bank accounts, obtain credit, file tax returns, register state taxes and more.
What is an Individual Taxpayer Identification Number?
An Individual Taxpayer Identification Number (ITIN) is a nine-digit tax processing number issued by the Internal Revenue Service (IRS) to individuals who are not eligible for an SSN but still need to fulfill their U.S. tax obligations. ITINs are primarily used by nonresident aliens, dependents, spouses of U.S. citizens or residents, and others who must file federal tax returns or report income under U.S. tax law.
What is a Preparer Tax Identification Number?
A Preparer Tax Identification Number is an identifier used by the Internal Revenue Service (IRS) identifier. Since 2010, a PTIN has been required for all paid federal tax return preparers. They must register with the federal government to acquire an identification number.
What is an Adoption Taxpayer Identification Number (ATIN)?
An Adoption Taxpayer Identification Number (ATIN) is a temporary nine-digit tax identification number issued by the Internal Revenue Service (IRS) for children in the process of being adopted who are not yet eligible for a Social Security Number (SSN). This number allows adoptive parents to include the child as a dependent on their federal tax return and claim applicable tax benefits, such as the Child Tax Credit.
Types of Taxpayer Identification Numbers (TINs)
| Type | Issuer | Who Needs It? | How to Apply |
| Social Security Number (SSN) | SSA | U.S. citizens, permanent residents, and authorized workers. | Apply using Form SS-5 and submit supporting documentation to the SSA. |
| Employer Identification Number (EIN) | IRS | Required for businesses to file taxes, hire employees, and open business bank accounts. | Apply online directly through the IRS. |
| Individual Taxpayer Identification Number (ITIN) | IRS | Nonresident aliens, spouses, dependents, and others without an SSN. | Use Form W-7 and submit supporting documents like a valid passport. |
| Preparer Tax Identification Number (PTIN) | IRS | CPAs, enrolled agents, and tax attorneys. | Apply online directly through the IRS. |
| Adoption Taxpayer Identification Number (ATIN) | IRS | Adoptive parents claiming a child as a dependent | Complete Form W-7A |
Common Questions About TINs
What if I’m not eligible for an SSN?
If you’re not eligible for an SSN but still need to meet U.S. tax obligations, you can apply for an ITIN. This number is specifically designed for nonresident aliens, their spouses, and dependents.
Can a business have multiple TINs?
Typically, a business has one EIN for tax purposes. However, individuals within the business, such as tax preparers, may have their own PTINs for professional use.
What happens if I don’t have a TIN?
Without a TIN, you won’t be able to file taxes or comply with IRS requirements, which can lead to penalties, delays in processing your tax returns, or even withholding of payments by employers or other entities.
How long does it take to get a TIN?
The processing time for a TIN varies based on the type. EINs, for example, are often available instantly when applied for online.
Do TINs expire?
Some TINs, such as ITINs, can expire if they are not used on a tax return for three consecutive years. In such cases, you’ll need to renew your ITIN before filing taxes. Other TINs, like SSNs and EINs, do not expire.
Can I use the same TIN for multiple purposes?
Yes, but it depends on the type of TIN. For example, an SSN can be used to file taxes, apply for credit, and report wages. However, ITINs are strictly for tax compliance and cannot be used for work authorization.
How do I verify a TIN?
The IRS provides a free TIN Matching service to help filers ensure they are submitting accurate information. This service benefits both parties: filers can avoid costly errors, while the IRS receives correct information, reducing the need for penalties or enforcement actions.
Sovos takes TIN Matching a step further with extended TIN Verification services. Our advanced tools streamline and scale TIN matching processes, enabling you to quickly verify data and identify potentially fraudulent individuals before establishing business relationships. Try TINCheck now for free.