Yes! You can use AI to fill out Form 3949-A, Information Referral

Form 3949-A, Information Referral, is used to report suspected violations of tax laws by individuals or businesses. This form is important for helping the IRS identify and investigate potential tax fraud and ensure compliance with tax regulations.
Form 3949-A is part of the referral forms category on Instafill.
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Form 3949-A has a moderate Form Complexity Index of 57/100 — 74 fillable fields across 1 page. Instafill’s AI completes it accurately in under a minute.

Form specifications

Form name: Form 3949-A, Information Referral
Form issued by: Internal Revenue Service
Number of fields: 74
Number of pages: 3
FCI: Moderate (57/100)
Version: 2020
Field instructions: Form 3949-A Instructions
Filled form examples: Form 3949-A Examples
Language: English
Our AI automatically handles information lookup, data retrieval, formatting, and form filling.
It takes less than a minute to fill out Form 3949-A using our AI form filling.
Securely upload your data. Information is encrypted in transit and deleted immediately after the form is filled out.
Preview of Form 3949-A, Information Referral

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How to Fill Out Form 3949-A Online for Free in 2026

Are you looking to fill out a FORM 3949-A form online quickly and accurately? Instafill.ai offers the #1 AI-powered PDF filling software of 2026, allowing you to complete your FORM 3949-A form in just 37 seconds or less.
Follow these steps to fill out your FORM 3949-A form online using Instafill.ai:
  1. 1 Visit instafill.ai site and select Form 3949-A.
  2. 2 Provide information about the person or business.
  3. 3 Describe the alleged tax law violation.
  4. 4 Fill in your contact information if desired.
  5. 5 Sign and date the form electronically.
  6. 6 Check for accuracy and submit the form.

Our AI-powered system ensures each field is filled out correctly, reducing errors and saving you time.

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Frequently Asked Questions About Form 3949-A

Form 3949-A has a Form Complexity Index of 57 out of 100, placing it in the moderate complexity tier. This score is calculated deterministically from the form’s own structure using Instafill’s published Form Complexity Index methodology, so it can be reproduced and independently verified — it is not a subjective estimate.

For Form 3949-A specifically, the score reflects 74 fillable fields across 1 page, grouped into 10 sections, plus 2 pages of printed instructions. The number of fields is the largest factor in the base score (weighted 36%), followed by how difficult those fields are to complete based on their type, where free-text and signature fields count for more than simple checkboxes (26%). The number of pages that actually contain fields (15%), the amount of conditional “fill-only-if” logic (16%), and how many sections the form is divided into (7%) account for the rest of the base. On top of that base, the index adds points for tables and repeating lists, bundled instruction pages, and dense page layouts — capturing difficulty the base alone can miss.

In practical terms, a moderate score means the form takes real effort: there are enough fields, pages and rules that errors are easy to make by hand. Instafill removes that effort entirely: our AI reads your information, maps each value to the correct field — including the conditional ones — and completes Form 3949-A accurately in under a minute, with every field available for you to review before you download. See exactly how the Form Complexity Index is calculated.

Form 3949-A is used to report suspected tax law violations to the Internal Revenue Service (IRS).

Any individual or business that suspects a tax law violation by another individual or business should use Form 3949-A to report it to the IRS.

The following information is required for reporting an individual: name, social security number or taxpayer identification number, date of birth, street address, city, state, ZIP code, occupation, email address, marital status, and name of spouse (if married).

The following information is required for reporting a business: business name, employer identification number (EIN), telephone number, street address, city, state, ZIP code, email address, and website.

Form 3949-A can be used to report various types of tax violations, including false exemptions, false deductions, multiple filings, organized crime, unsubstantiated income, earned income credit, public/political corruption, false/altered documents, unreported income, narcotics income, kickback, wagering/gambling, failure to withhold tax, failure to file return, failure to pay tax, and other violations.

If unreported income and tax years are known, they should be reported by filling in the tax years and dollar amounts in the appropriate sections of the Form 3949-A.

Additional information should be provided in Section B, if possible. This can help the IRS process the form more efficiently and accurately.

If the reported taxpayer is considered dangerous, the IRS will take appropriate measures to ensure the safety of their employees and the public. This may include notifying the appropriate authorities.

The person reporting's name, telephone number, best time to call, street address, city, state, and ZIP code are optional but helpful if the IRS needs to contact them for additional information.

The completed Form 3949-A should be sent to the Internal Revenue Service at PO Box 3801, Ogden, UT 84409.

Form 3949-A does not have a specific deadline for submission. However, it is strongly recommended to submit the form as soon as possible after discovering a suspected tax law violation.

Yes, there is a reward program for providing original information leading to the discovery of tax law violations. To apply for a reward, use Form 211, Application For Award For Original Information.

Form 3949-A should not be used to report suspected misconduct by a tax return preparer, to report identity theft, or to report abusive tax avoidance schemes or promoters.

Compliance Form 3949-A
Validation Checks by Instafill.ai

1
Ensures that all required fields in Section A for an individual are completed
The AI ensures that Section A of the Information Referral Form 3949-A is thoroughly reviewed when reporting an individual. It checks for completeness of all mandatory fields such as the individual's name, Social Security Number (SSN) or Taxpayer Identification Number (TIN), date of birth, address, occupation, email, and marital status. If the individual is married, the AI also verifies that the spouse's name is provided. This validation is crucial to ensure that the IRS has sufficient information to identify and investigate the individual in question.
2
Confirms that all required fields in Section A for a business are filled out
When reporting a business, the AI confirms that all necessary information in Section A is accurately filled in. It checks for the business name, Employer Identification Number (EIN), contact telephone number, physical address, email address, and the business's website if known. This comprehensive check is essential for the IRS to have the correct details to proceed with any investigation into the reported business's tax matters.
3
Verifies that both parts of Section A are completed if reporting a business and its owner
In cases where the Information Referral Form 3949-A pertains to both a business and its owner, the AI verifies that both parts of Section A are fully completed. This dual verification process ensures that the IRS receives all pertinent information about the business entity as well as personal details about the owner, which is necessary for a thorough examination of the tax violation allegations.
4
Checks that all applicable boxes for alleged tax violations in Section B are marked
The AI checks Section B of the form to ensure that all relevant boxes indicating the type of alleged tax law violations are marked. This includes scrutinizing the form for any indications of false deductions, unreported income, or other tax-related offenses. By confirming that the appropriate boxes are checked, the AI assists in providing clear communication to the IRS regarding the nature of the suspected violations.
5
Validates the inclusion of detailed descriptions in Section B
The AI validates that Section B contains detailed descriptions of the alleged tax violations, including unreported income. It ensures that specific details such as the tax years involved and the estimated dollar amounts, if known, are included. This validation is critical as it provides the IRS with the necessary context and magnitude of the potential tax issues, enabling a more effective investigation process.
6
Comprehensive Description of Alleged Violation
Ensures that Section B of the Information Referral Form 3949-A contains a detailed account of the alleged tax violation. It confirms the presence of a comprehensive description, including the specifics of 'who' is involved, 'what' the violation is, 'where' it took place, 'when' it occurred, and 'how' the information was obtained. This validation check is crucial for the IRS to understand the nature of the alleged violation and to assess the credibility and detail of the report.
7
Attachment Formatting and Reference
Verifies that any additional sheets attached to the Information Referral Form 3949-A for the purpose of describing the alleged violation are properly formatted according to IRS guidelines. It ensures that these attachments are clearly referenced within the form, allowing for a seamless review process. This check is important to maintain the integrity of the information provided and to ensure that all supplementary documents are easily identifiable and accessible.
8
Completion of Additional Questions in Section B
Confirms that the informant has completed the additional questions in Section B of the Information Referral Form 3949-A. This includes verifying whether the informant has provided information regarding the availability of books and records, any perceived danger from the taxpayer, and the identification of banks or financial institutions used by the taxpayer. This validation check is essential to gather as much relevant information as possible to aid in the investigation of the alleged violation.
9
Informant's Contact Information in Section C
Checks that Section C of the Information Referral Form 3949-A is filled out with the informant's contact information, should they choose to provide it. This includes verifying the informant's name, telephone number, the best time to call, and address. This validation check is important for the IRS to have the option to follow up with the informant for additional information or clarification, while also respecting the informant's choice to remain anonymous if they prefer.
10
Form Print and Send-off Readiness
Ensures that the Information Referral Form 3949-A is printed and ready to be sent to the correct Internal Revenue Service address as provided in the form's instructions. This validation check is the final step to confirm that the form is properly prepared and that the informant has the correct mailing information, facilitating the timely and accurate submission of the report to the IRS.
11
Privacy Act and Paperwork Reduction Notice Acknowledgment
Ensures that the informant has been presented with the Privacy Act Notice and Paperwork Reduction Notice associated with the Information Referral Form 3949-A. It confirms that the informant understands their rights regarding the information they provide and how it will be used. This validation check is crucial to maintain compliance with legal requirements and to ensure informed consent from the informant.
12
Appropriate Use of Form 3949-A
Validates that the Information Referral Form 3949-A is utilized for its intended purpose and not for reporting issues outside its scope. This includes ensuring the form is not used for matters such as identity theft, tax return preparer misconduct, unauthorized changes to a return by a preparer, claiming exemptions or dependents, reporting abusive tax avoidance schemes, or reporting misconduct by tax-exempt organizations. This check helps maintain the integrity of the form's use and directs informants to the correct forms for other types of issues.
13
Alternative Form 211 for Rewards
Ensures that if the informant is seeking a reward for providing information, they are directed to use Form 211 instead of Form 3949-A. This validation check is important to guide informants to the appropriate form for reward claims and to prevent the misuse of Form 3949-A, which is not designed for reward claims.
14
Completeness of Information
Verifies that the Information Referral Form 3949-A is fully completed and does not lack any critical information that would render it incomplete or invalid. This check is essential to ensure that all necessary details are provided to process the referral effectively and to avoid delays or rejections due to incomplete submissions.
15
Accuracy of Information
Checks for any obvious errors or inconsistencies in the information provided on the Information Referral Form 3949-A. This validation ensures that the data entered is logical and coherent, which is vital for the accurate processing of the form and for the subsequent investigation or action that may be required based on the referral.

Common Mistakes in Completing Form 3949-A

Incomplete or inaccurate information in Section A

Failure to provide complete and accurate information in Section A of Form 3949-A can lead to processing delays or even rejection of the form. For individuals, omitting their SSN or date of birth can cause issues. For businesses, neglecting to provide their EIN can result in similar complications. To avoid this mistake, ensure all required information is provided in full and double-check for accuracy before submitting the form.

Incorrectly checking boxes or failing to check all applicable boxes in Section B

Section B of Form 3949-A requires taxpayers to check all boxes that apply to the alleged tax violation. Failing to check the correct boxes or not checking all applicable boxes can result in incorrect processing of the form. To prevent this mistake, carefully review the instructions for Section B and check all boxes that correspond to the alleged tax violation(s).

Insufficient details of unreported income and tax years in Section B

Providing insufficient details of unreported income and the tax years involved in Section B can hinder the IRS's ability to properly investigate the alleged tax violation. To avoid this mistake, be as specific as possible when describing the unreported income, including the nature of the income, the amount, and the tax years involved. Additionally, ensure all required information is provided to the best of your ability.

Unclear or incomplete descriptions of alleged tax violations in Section B

Failing to describe the facts of the alleged tax violation clearly and concisely in Section B can lead to confusion and delays in the investigation process. To prevent this mistake, provide a detailed and accurate description of the alleged tax violation, including the specific tax laws that were violated, the amount of tax due, and any relevant documentation or evidence. Be sure to answer all questions in Section B, including those regarding the availability of books/records and the danger level of the taxpayer.

Incomplete contact information in Section C

One of the most common errors on the Information Referral Form 3949-A is the failure to provide complete contact information in Section C. This section requires the submitter to provide their name, address, and telephone number. It is essential to ensure that all fields are filled out accurately and completely to facilitate proper processing of the form. Incomplete contact information may result in delays or even rejection of the form. To avoid this mistake, double-check all contact information before submitting the form.

Sending the form to an incorrect address or failing to send it to the Internal Revenue Service

Another common mistake on the Information Referral Form 3949-A is sending the form to an incorrect address or failing to send it to the Internal Revenue Service at all. It is crucial to follow the instructions carefully and send the form to the correct address to ensure timely processing. Failure to send the form to the IRS may result in delays or even the rejection of the form. To avoid this mistake, double-check the mailing address provided on the form and ensure that it is complete and accurate before mailing the form.

Using the form for issues other than reporting suspected tax law violations

Ignoring the instructions and using the Information Referral Form 3949-A for issues other than reporting suspected tax law violations is a common mistake. This form is specifically designed for reporting suspected tax law violations to the IRS. Using it for any other purpose may result in delays or even rejection of the form. To avoid this mistake, carefully read and follow the instructions provided on the form before filling it out.

Ignoring the Privacy Act Notice and Paperwork Reduction Notice

Failing to read and understand the Privacy Act Notice and Paperwork Reduction Notice before filling out and submitting the Information Referral Form 3949-A is a common mistake. These notices provide important information about how the IRS will use the information provided on the form and the time required to complete it. Ignoring these notices may result in unintended consequences or delays. To avoid this mistake, carefully read and understand the Privacy Act Notice and Paperwork Reduction Notice before filling out and submitting the form.
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