A Tax Identification Number (TIN) is a number used to identify a taxpayer for U.S. federal tax administration and reporting. It can identify an individual or an organization on tax returns and other tax documents. A TIN may also appear in records that report payments to the IRS. The term refers to several types of identifiers, including a Social Security number (SSN), an Employer Identification Number (EIN), and an Individual Taxpayer Identification Number (ITIN). The appropriate type depends on who the taxpayer is and why the number is needed. A TIN is not a single number that everyone obtains from the IRS. Having one does not by itself establish work authorization or determine worker classification. It also does not establish how much tax a person or organization owes.
Table of Contents
- Which Numbers Count as U.S. Tins?
- How Do You Choose the Right Tin for Form W-9?
- Where Is a Tin Used in Payroll and Tax Reporting?
- How Do You Obtain or Recover a Tin?
- What If a Tin Is Missing or Incorrect?
- Why Do Tins Matter in Contingent Workforce Management?
Which Numbers Count as U.S. Tins?
The IRS recognizes five main types of TIN. Most individuals use an SSN, which is issued by the Social Security Administration. Businesses and other qualifying entities commonly use an EIN. Despite the word “Employer” in its name, an EIN may identify an entity that has no employees.
An ITIN is for a person who needs a U.S. federal tax number but is not eligible for an SSN. It is for federal tax purposes only. It does not grant Social Security benefits or change immigration or employment status. An Adoption Taxpayer Identification Number (ATIN) is temporary. It applies in certain pending domestic adoptions when a child’s SSN is not available in time for tax filing. A Preparer Tax Identification Number (PTIN) identifies a paid federal tax return preparer. It is not a substitute for the taxpayer’s own TIN. The IRS describes these categories on its TIN overview.
How Do You Choose the Right Tin for Form W-9?
Form W-9 lets a payer request a U.S. person’s TIN and certain tax certifications. The completed form is generally given to the requester rather than sent to the IRS. The name and number should identify the same taxpayer. A business name used on an invoice does not necessarily tell the payer which person or entity is the taxpayer for reporting purposes.
For a sole proprietor or a single-member LLC treated as a disregarded entity for federal income tax purposes, the W-9 generally identifies the owner on line 1 and the business name on line 2. The owner’s SSN or EIN is generally used for income tax information reporting rather than the disregarded LLC’s EIN. Other business structures may report under their own EIN. Check the current form instructions when ownership or federal tax classification affects the answer. A non-U.S. person may need an appropriate Form W-8 instead. Having a U.S. TIN alone does not determine which tax form applies.
Where Is a Tin Used in Payroll and Tax Reporting?
In payroll, the worker’s and employer’s identifiers serve different purposes. An employee’s SSN identifies the person receiving wages on Form W-2. The employer’s EIN identifies the organization reporting wages and employment taxes. The employer uses its EIN on federal filings such as Form 941, a quarterly return used by many employers to report employment taxes. A number entered for the wrong taxpayer can misdirect reporting even if the payment amount is correct.
TINs are also used outside payroll. A payer may request a recipient’s number before filing an information return for certain payments. Some eligible payers can use the IRS TIN Matching service to check a name-and-number combination before filing. A TIN identifies the taxpayer in reporting. It does not decide whether a payment is wages, contractor income, or another type of income. The payment and applicable tax rules determine the reporting and tax treatment.
How Do You Obtain or Recover a Tin?
First identify who needs the number and why. Apply for an SSN through the Social Security Administration if eligible. An individual who needs a federal tax number but cannot obtain an SSN may qualify for an ITIN by applying to the IRS with Form W-7. The application generally requires supporting identity and foreign-status documents. A federal tax return usually accompanies it unless an IRS exception applies.
An eligible applicant can request an EIN directly from the IRS. The IRS provides its online EIN application at no charge and sets eligibility requirements for using it. A PTIN is obtained separately by a paid tax return preparer. An ATIN applies only to qualifying adoption circumstances. If a number has been lost, the taxpayer should generally retrieve or verify the existing number through the issuing agency rather than applying for a duplicate. SSNs and ITINs are not interchangeable choices based only on preference.
What If a Tin Is Missing or Incorrect?
A missing number or a mismatch between the taxpayer’s name and number can interfere with information reporting. The payer may need corrected documentation and may have to follow IRS notice procedures. Some reportable payments may be subject to federal backup withholding when a payee fails to provide a correct TIN or another specified condition applies. The IRS states that the rate is 24% for payments subject to backup withholding. The rule does not apply to every payment. Amounts withheld are generally reported as federal tax withheld on the recipient’s return.
When a discrepancy arises, check that the number belongs to the taxpayer named on the form and that the name matches the relevant agency record. Follow any IRS notice rather than assuming an internal record change resolves the issue. TINs are sensitive personal information. Collect them through secure channels and limit access to people who need them for authorized tax reporting or administration.
Why Do Tins Matter in Contingent Workforce Management?
For a contingent worker, the appropriate tax documentation depends first on the worker’s actual classification and the entity responsible for payment. The IRS bases federal worker classification on the facts of the working relationship. Those facts include control and independence. A person’s EIN or a signed W-9 does not by itself make that person an independent contractor. The IRS explains the distinction in its guidance on employees and independent contractors.
In an employer-of-record or payrolling arrangement, the program should make clear which organization employs the worker and handles wage reporting. Employee payroll documentation uses the employee’s identifying information and the employer’s reporting details. For a worker properly treated as an independent contractor, the payer may collect a W-9 and use the contractor’s TIN for required information reporting. TCWGlobal’s contingent workforce management work may involve coordinating these processes within a workforce program. Programs with workers in more than one country should distinguish U.S. TINs from foreign tax identifiers and use the documentation required for each jurisdiction.
