What this letter is about

We are sending you Letter 12C because we need more information to process your individual income tax return. This information can include:

  • Missing forms or schedules to support your entries on Form 1040 or Form 1040-SR
  • Verification of income, withholding, and credit amounts.
  • Documentation to reconcile advance payments of the Premium Tax Credit (PTC). Please refer to PTC page for more information on PTC advance payments.  

What you need to do

  • Read your letter carefully and respond timely.
    • Respond to the letter, even if you disagree with the information in it.
    • Send us a letter explaining what information you think is in error.
    • Send the information we requested.
  • Do not file a Form 1040-X, Amended U.S. Individual Income Tax Return. When we receive the requested information, we’ll use it to process your original tax return.
  • If you’re due a refund, we’ll send it about 6-8 weeks after we receive your response.

How to respond

  • Fax your information to the fax number in the letter using either a fax machine or an online fax service. Several online fax services use the internet to send files from your computer or smart device to a fax number.
  • You can also mail your information to the address shown at the top of the letter.
  • Include a copy of the letter with your response.

You may want to

Visit  our Affordable Care Act page for more information about filing a tax return with Form 8962, Premium Tax Credit (PTC).


More information you may find useful