To ensure timely payment, suppliers should follow standard invoicing instructions.
External Services Management (ESM) is a process for receipt, verification, and payment for services based on an approved quantity of services at agreed upon rates. Suppliers who have been established to utilize this process should follow one of the following methods for invoicing.
For all subcontractors, suppliers must submit a completed Waiver of Lien along with or prior to submitting the final invoice to the Lyondell buyer (as identified in the contract).