Payer Identification Number (TIN) or Taxpayer Identification (TIN) Registration Program. Download a Schedule. Download an Instructions/Instructions For Individuals. Find a Permit or TIN Registered Business. Download a Form. Forms for Filing Schedule A, W-2, G-1, or I-9, and Payment of Federal and State Taxes. Download an Instruction/Instructions For Non-Profit Organizations. Forms in Latin American Languages Tax Return Filing Tips and Advice Need a Taxpayer ID? You must know your taxpayer ID number (TIN), such as your Social Security Number. To receive a California tax number, click here. Taxpayers Identification Numbers (Tins) or Taxpayer Identification Numbers (Tins) are required on some of your tax forms and documents. Each TIN was awarded through a competitive, merit-based selection process conducted by the Internal Revenue Service. The IRS does not provide a TIN. Read our FIND AN IRS TIERED REASONS TO FILE A TAX RETURN article for more information. Download the Instructions and Instructions For Individuals, to see detailed instructions on how to use Form W9, Request for Taxpayer Identification Number. You will also need to print Form W-9. Then, if you need more documents to complete your form, select from the menu “File, Print, and complete a Form”. Read our IRS Filing Tips article for more information on using software to prepare your return based on information provided in our FAQ section. If you are having trouble with this site, please contact us for help. We'd like to hear what you think! The most helpful comments come from people who take the time to read the explanations and give us their opinions, or at least provide a better idea of how others who don't have as much experience understand the process.