Tax & Remittance FAQs


FAQs for Vendor Claims Processing


This information has been prepared for its intended purpose only, and is not intended to provide, and should not be relied on for tax, legal or accounting advice.  You should consult your own tax, legal and accounting advisors.

  • Why do you need my Tax Identification Number (TIN) and what is a W9 Form?
    1. The County is required to provide a document to the IRS which reports payments made to you as a County Vendor.  This document is called an “Information Return.”  In order to properly file this Information Return, the County is required by the IRS to collect your Tax Identification Number (TIN) and other information.  The County cannot make payments to you without having first received this information.   This information is provided by you to the County utilizing IRS form W-9. 
    2. Form W-9 is officially titled the “Request for Taxpayer Identification Number and Certification.” This form is used to provide the correct Taxpayer Identification Number (TIN) to the person who is required to file an Information Return with the IRS to report transactions including vendor payments, non-employee compensation, real estate transactions, mortgage interest, acquisition or abandonment of secured property, cancellation of debt, etc.
  • Where can I find help in completing my W9?
    1. Current copy of IRS Form W9 is available at .
    2. The IRS provides an informational video to assist in completing your W9, you may view the video here:
  • What is my “Legal Name” for purposes of the W9? 
    1. Line 1 of Form W-9 asks for your name. If you are running a sole proprietorship, you would enter YOUR name, for example. The name on line 1 must match the name the IRS associates with your TIN.
    2. The name on line 1 should never be a disregarded entity – a single owner LLC. If the owner of a single member LLC is also a disregarded entity, provide the name of the first owner that isn’t a disregarded entity and their TIN.
    3. If you have a business name, trade name, Doing Business As (DBA) name or disregarded entity name, you can enter it on line 2, business name.
    4. On line 3, select just ONE box. Check the appropriate box for the U.S. federal tax classification of the person whose name is entered on line 1.
  • How does the County use the information from my W9?
    1. Nassau County uses the IRS’s Taxpayer Identification Number Matching Application to verify Legal Names and TIN numbers of all vendors. Nassau County is only able to accept Legal Name and TIN numbers which match IRS records.
    2. Information regarding the IRS’s Tax ID Matching Application and how the program is used is available at
  • Who will have access to my W9 and other tax information?
    1. As per IRS guidelines, W9s will be kept on file for each vendor registered with Nassau County and will be used to authorize and record payments in the Nassau County Financial Systems. Your tax information is available upon request to the IRS, New York State Department of Taxation and Finance and other authorized requesters. 
  • What happens if my Tax Identification Number (TIN) and Legal Name do not match?
    1. If your TIN and Legal Names do not match, interruptions or delays in payments may occur until the issue is resolved.
    2. Nassau County is not responsible for such disruptions nor is it obligated to assist in correcting any discrepancies. If you notice any issue, please contact your attorney or tax professional for more information.  
  • What happens if I use a Doing Business As (DBA) name and how does the County verify it?
    1. The IRS only uses your Legal Name, it does not track Doing Business As (DBA) or alternate names that may be used by any particular entity or individual. 
    2. Doing Business As (DBA) or alternate names, are traditionally registered with the respective agency in the State your business is registered with. For example, if you are registered with New York State Secretary of State, a record of your alternate names is available to the public at
    3. If yours is a publicly traded corporation, Nassau County may also use copies of your SEC filings to verify dbas or alternate names. This information is available to the public at .
    4. If you changed your business name, you must file separate requests with the respective State agency and the IRS for the names to match.
  • What happens if the IRS and the State I am registered with have different information?
    1. The IRS and each State businesses regulator operate independently. Therefore, if you update your information with one, you are required to update your information with the other(s). 
    2. One common mistake is that you may file an amendment to your Articles of Incorporation or a Merger Agreement with your respective state agency, but forget to file them with the IRS separately.  
  • What if I elect to use a Disregarded Entity for County payments? 
    1. If electing to use a Disregarded Entity, you may either use (1) the parent company’s TIN and their name or (2) the Disregarded Entities TIN and their name; you are prohibited from “mixing and matching” TIN and Legal Name information. 
    2. For more information, please refer to the IRS at .
  • What tax information should I expect to receive from Nassau County?
    1. Nassau County will issue 1099 forms to certain recipients of previous year payments.
    2. If you are required to receive a 1099, it will be mailed to you and reported to the IRS no later than January 31. 
    3. Please refer to the IRS guidance on 1099 reporting and responsibilities at 
  • Who should I contact for more information?
    1. The Comptroller’s Vendor Claims Division is available from 8 a.m. – 4:45 p.m. Monday to Friday to assist with or answer any questions regarding tax and/or remittance information. You may contact us via our Helpline at (516) 571-3241 or


  • What should I do if some of my information does not appear correct, such as my Tax Identification Number or Legal Name?
    1. If your TIN or Legal Name is incorrect on the Vendor Portal, please return to your dashboard and correct the information that you entered when you first registered on the Nassau County Vendor Portal.
  • Why do I need to answer the first few questions on the W9 Form?
    1. Answering the questions provided will help Nassau County determine if a 1099 needs to be reported to the IRS as a result of the County’s payment to you. 
  • Why am I being asked to provide a voided check or bank letter?
    1. The Comptroller’s Office has a variety of controls in place to ensure the accuracy and safe handling of your banking information. Similar to how your Tax Identification Number is verified with the IRS, your banking information, to the extent possible, will be verified by our bank to ensure no issues occur in delivery of ACH payments. 
    2. Please note that for security reasons the following will not be accepted:
      • Deposit Slip
      • Reorder Slip
      • Direct Deposit form
      • Bank Letter without a contact listed.
      • A voided check or bank letter that has been altered or redacted.
  • What do you mean by Bank Letter?
    1. As part of the County’s verification process, you may be required to submit a letter confirming that you are a customer, the title of the account and the banking information associated with that account. The letter must be on bank letterhead and include a name and contact information of an individual that could be contacted in the event of an issue.
  • Are Post Office (P.O.) Box mail addresses acceptable?
    1. Yes. Nassau County is able to mail payments to P.O. Boxes, as well as to third-party lock boxes.
  • Does Nassau County accept Universal Payment Identification Code (UPICs)?
    1. According to, a UPIC® is a unique account identifier issued by a financial institution that allows organizations to receive electronic payments without divulging confidential banking information. More information is available at
    2. If your banking institution provides you with a UPIC, please submit that information in lieu of your actual banking information.
    3. A bank letter should still be provided, verifying the UPIC information being submitted.
    4. The County’s verification services should be able verify the UPIC with your bank.
    5. Please note that UPICs are relatively new, and you may be contacted if more information is needed.
  • Can Nassau County send international payments?
    1. The County cannot send international payments.  If you are a foreign entity, please contact your bank for more information. In many instances, your home bank may have agreements in place to use an intermediary bank/financial partner in the United States.
  • Does the Comptroller’s Office make payments?
    1. The Office of the Nassau County Comptroller is responsible for ensuring correct remittance information and reviewing claims to ensure payments are accurate; however, the actual ACH or check you receive will be processed by the Nassau County Treasurer’s Department. 
  • Who should I contact for more information?
    1. The Comptroller’s Vendor Claims Division is available from 8 a.m. – 4:45 p.m. Monday to Friday to assist with or answer any questions regarding tax and/or remittance information. You may contact us via our Helpline at (516) 571-3241 or