The State of Delaware eSupplier Portal is a secure login site for new suppliers to register and existing suppliers to manage their information. The State does not accept IRS Form W-9, instead all suppliers are required to register through the eSupplier Portal.

Successful submission and approval of a new supplier registration enables the creation of a State of Delaware supplier record. The Taxpayer ID (SSN or EIN) and supplier name are submitted to the Internal Revenue Service for "matching." If the Taxpayer ID and name do not match, the supplier record cannot be approved.

Existing suppliers who have not previously registered through the eSupplier Portal will need to obtain a user ID and password in order to submit changes to their State of Delaware supplier record.

Detailed instructions for submitting new registrations, obtaining user IDs and passwords, and submitting change requests are located on the FAQs / Contact Us page of the eSupplier Portal.

Note: The eSupplier Portal does not contain invoices, payment history, or payment details for payments made to suppliers.

If you have questions about completing this form or specific comments about a form that you have submitted, please contact the supplier maintenance team by phone at 302-672-5000 or by email at

Click the link below to access the State of Delaware eSupplier Portal:

Please be advised:

Effective May 7, 2018 the State of Delaware has discontinued use of the State of Delaware Substitute Form W-9. All new Supplier registrations and existing Supplier change requests must be submitted through the eSupplier Portal.

Note: Any information previously submitted through the Delaware Substitute Form W-9 process prior to May 7, 2018 remains active and on record. Existing Suppliers will only need to access the eSupplier Portal when an update to their information is required.

Click here for an overview of the new State of Delaware eSupplier Portal.

Click here to view the 4/25/18 awareness communication.