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The options for a supplier to update their payment address depends on the nature of the supplier's business relationship with King County.

Suppliers with grant-related contracts must contact the agency providing the grant in order to have their payment address updated. The supplier will need to provide a new KC W-9 for tax identification verification.

Suppliers with contracts with King County must have an spend-authorized account in the E-Procurement Supplier Portal. Once that is set up, suppliers can maintain their payment information through the Supplier Portal. If the supplier does not have a spend-authorized account, they can set one up with the following steps.

  1. Register in the Supplier Portal if they have not already done so.
  2. Attach a KC W-9 to their Supplier Portal account for tax identification verification.
  3. Contact the Procurement & Payables employee who manages the contract, and request that the supplier profile is promoted to "spend authorized". To find the name of the Procurement & Payables employee, look up the contract on the Awarded Contracts Log
  4. Once the account is promoted to spend authorized, the supplier can manage their payment address through their account. 

Suppliers must contact either the agency they work with or Central.AP@kingcounty.gov. The supplier must provide a new KC W-9 for tax identification verification.

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