1. Why do you need my SSN or taxpayer ID?
The IRS requires CEX.IO to collect your Taxpayer Identification Number (e.g. SSN) to verify your identity and to accurately report your crypto transactions to the Internal Revenue Service (IRS). This helps ensure that your trading activity is properly reflected in your annual tax documents.
2. How will my SSN or taxpayer ID be used?
Your SSN is used exclusively for identity verification and tax reporting purposes. We share this information only with the IRS as part of mandatory reporting (e.g., Form 1099-DA). We do not sell, rent, or use your SSN for marketing or credit-related activities.
3. Is this information safe?
Yes, we protect your personal data using strong encryption and follow strict security measures. Only authorized personnel can access this information for compliance purposes, and we adhere to federal data protection standards and industry best practices.
4. What is Form W-9?
Form W-9 is a form required by the IRS to collect your taxpayer information. By filling out this form, you are providing your Taxpayer Identification Number (e.g. SSN) so we can report your digital assets activity to the IRS. This is part of our legal obligation to report certain transactions, such as through Form 1099-DA. Additional information on Form W-9 can be found here.
5. What if I don’t provide my SSN?
If you do not provide the required information, you may not be able to use our service and we would be unable to report your transactions correctly, and it could cause delays
6. What happens if my personal information changes?
If your name, taxpayer identification number, or other details change, you must update us right away. Provide the necessary documents and a new W-9, and we will use the updated data on our report with the IRS.
7. What happens if I make a mistake or provide incorrect information?
If your information is wrong, please update us immediately. You are responsible for making sure the details are correct, as it impacts your tax reporting. By certifying, you are confirming that the information you provided is accurate. This is a legal requirement from the IRS.
8. I am subject to backup withholding. How does that affect my W-9 form?
Indicating that you are subject to withholding, will have the effect of crossing-out the statement that you are NOT subject to backup withholding. Your clicking “Agree” will certify that all other statements about your taxpayer identification, citizenship and FACTA codes (if applicable) are correct.
9. Backup withholding
Starting January 1, 2027, you will be subject to backup withholding if you have not verified your Form W-9 or W-8 information with CEX.IO, as mandated by the IRS.
Backup withholding requires financial institutions to withhold a portion of payments to certain customers and remit it to the IRS. The rate is currently 24% on all proceeds, with some states requiring an additional percentage.
Prevent backup withholding by verifying your Form W-9 or W-8 information.
Source: IRS Form W-9 and IRS Form W-8BEN
10. What is a U.S. Person?
For tax purposes, a "US person" is defined as:
A citizen of the United States
A person who meets the green card test↗ or substantial presence test↗ for the calendar year
Source: IRS Form W-9
11. What are FATCA Codes?
FATCA (Foreign Account Tax Compliance Act) codes are used by financial institutions, including CEX.IO, to identify the tax status of their account holders. Some key points about FATCA codes:
FATCA codes indicate whether an account holder is a U.S. person for tax purposes or a non-U.S. person.
Common FATCA codes include W-8BEN (for non-U.S. persons) and W-9 (for U.S. persons).
Providing the correct FATCA code helps ensure CEX.IO complies with U.S. tax reporting requirements.
12. IRS Forms W-9 and W-8
All customers of CEX.IO, Inc. are required to verify their IRS Form W-9 or W-8 information with CEX.IO by January 1, 2026, per new IRS tax reporting regulations.
Form W-9 allows US persons to provide and certify their Taxpayer Identification Number (TIN) or Social Security Number (SSN), name, address, and exemption from backup withholding
Form W-8 allows non-US persons to provide and certify their foreign status, name, address, and applicable tax treaty benefits
For tax purposes, US persons are citizens of the United States or persons who meet either the green card test or substantial presence test for the calendar year
CEX.IO uses this information to report taxable income to the IRS when required. Ensuring this information is correct helps prevent tax reporting issues.
If the information you used to create a CEX.IO account doesn’t match the information on your Form W-9 or W-8, you’ll need to make corrections and submit your form for reverification.
Common reasons for reverification include:
Name mismatch – Your name must match the Social Security Administration (SSA) or IRS records, including suffixes (e.g., "Jr." or "III")
Incorrect TIN – Your TIN must exactly match the SSA or IRS records
Expired documents – Form W-8 and the supporting documentation you submit expire, and you’ll be required to submit a new Form W-8 when this happens
Visit IRS.gov for more information, including how to contact the Social Security Administration.
The web content provided by CEX.IO is for educational purposes only. The information and tools provided neither are, nor should be construed as, an offer, or a solicitation of an offer, or a recommendation, to buy, sell or hold any digital asset or to open a particular account or engage in any specific investment strategy. Digital asset markets are highly volatile and can lead to loss of funds.
The availability of the products, features, and services on the CEX.IO platform is subject to jurisdictional limitations. To understand what products and services are available in your region, please see our list of supported countries and territories. This page includes additional links to information about individual products, and their accessibility.