Every year Westlake Vinnolit buys large amounts of raw materials, goods and services. Intelligent procurement management ensures that all relevant factors are cost-effective and available on time and in the correct quantities. Quality, reliability of supply, sustainability and innovation are just as important in this context as partnerships based on fair collaboration with our suppliers and service providers.

Our procurement team looks forward to hearing from you!

Purchasing conditions

Please also take note of the Westlake Sustainable Procurement Policy 

Supplier management

Focused supplier management with a competent pool of long-standing and new suppliers is our guarantee of success with effective procurement processes.

Would you like to become one of our suppliers?

You can find out further information and how to register from:

Westlake Vinnolit GmbH & Co. KG
Carl-Zeiss-Ring 25
85737 Ismaning, Germany


Processes & systems

You can be approved for access to Westlake Vinnolit transport tenders through the provider TRANSPOREON.

Ticontract Carrier Tendering

Transport orders are sent fully automatically to the freight companies via EDI through the provider Mercoline or by fax/email.

Please note in connection with EDI:
Guide to EDI (following shortly)

In all plants, TISLOT Light is used as the system for managing the loading window through the provider Transporeon . It is obligatory for all collectors to book a loading window there using the transport number.
To the login for self-collection & freight companies:
TISLOT Light Login
TISLOT Light Login manual

Westlake Vinnolit has met all the statutory requirements for electronic receipt of invoices in PDF format. We therefore provide the option for our suppliers to send us their invoices by email. This form of invoicing is much faster and more cost-effective, and it also benefits the environment. If you wish to participate, please notify us by fax, post or email of when you wish to switch to electronic invoicing by submitting a signed consent form.

Please note the following:
· Send your invoices in PDF format exclusively to:
· Only one PDF file per invoice; invoice attachments must be part of the PDF file.
· PDF files should not include a signature or verification.
· PDF files must not be password protected.
· After you switch to electronic invoicing, we will unfortunately no longer be able to accept any paper invoices.

If you have any questions about electronic invoicing, the process or transmission format, please contact:

Westlake Vinnolit GmbH & Co. KG
Carl-Zeiss-Ring 25
85737 Ismaning, Germany



Westlake Vinnolit is certified according to ISO 9001 (quality management), 14001 (environmental management) and 50001 (energy management), as well as ISO 45001 and OHRIS (both occupational safety). Compliance with the relevant standard requirements is confirmed by independent auditors in regular audits.