Reporting Security Incidents

If you are a current supplier and need to report a security incident, please contact your primary Marsh & McLennan account contact by phone. In the event you are unable to reach such contact promptly, send an email to

Please include: (a) a description of the incident, including its impact; (b) the expected resolution time (if it has not already been resolved); (c) corrective measures to be taken, evaluation of alternatives and next steps; and (d) the name and phone number of the supplier representative for us to contact to obtain further information and updates.


Ethics Hotline

Marsh & McLennan Companies’ Suppliers are held to the same standards as our colleagues, as outlined in MMC’s Greater Good.  If you are a current supplier and have an ethical issue you would like to report, you may use MMC’s Secure Ethics & Compliance Line.

The Ethics & Compliance Line is a comprehensive and confidential reporting tool supplied by specialist provider NAVEX Global to assist in addressing allegations of fraud, abuse, and other misconduct in the workplace, all while cultivating a positive work environment. The Ethics & Compliance Line is an important part of our culture, and assists us in creating a safe, secure, and ethical workplace. You are encouraged to seek guidance on ethical dilemmas, provide positive suggestions, or communicate a concern. Effective communication is critical in today’s workplace and this is a great tool to enhance that communication.

Invoicing Marsh & McLennan

For goods and services supplied to our Marsh & McLennan Companies, Marsh, and Guy Carpenter businesses (anywhere in the world), as well as Mercer, Oliver Wyman Group, and NERA business (only in US, UK, Ireland, Canada, Australia, New Zealand, Hong Kong, and Singapore) you are required to have a Purchase Order (PO) in your possession before billing us. Once you have the PO, and you have supplied the goods or services requested you can invoice us as follows:


For goods and services supplied to Mercer and Oliver Wyman Group businesses, outside of the territories detailed above, a Purchase Order is not required.

Once you have supplied the goods or services requested our preference is that you invoice us via email (in PDF format) to your business contact. If this route is not available then you can invoice us via the below email addresses, but this may delay payment.

  • Always include the name of the business contact on the invoice to help processing. 
  • If you have already submitted an invoice to an office location that may not be manned, please resend the invoice as a pdf via email directly to Accounts Payable.

Europe, Middle East & Africa:

Latin America:

Please send invoices as instructed by your local business contact. 

Electronic Invoicing

Marsh & McLennan Companies has partnered with Tungsten Network to provide a simpler way for suppliers to submit invoices. By joining the Tungsten Network, you will experience greater efficiencies from Marsh & McLennan Companies' Accounts Payable department. This initiative is key to our strategy moving forward and we are confident you will see significant benefits to your business.

  • Fast, guaranteed invoice delivery. Invoices are received automatically and securely against any valid MMC purchase order listed in the Tungsten portal
  • Early invoice data validation. Tungsten Network validates supplier invoice data at time of entry, streamlining approval
  • Greater visibility of invoice status.   Suppliers no longer need to chase invoices, but can instead see status at any stage
  • On-time payments.  Improves supplier cash-flow
  • Tungsten HelpDesk and Support. Suppliers have access to the Tungsten HelpDesk for invoicing support and assistance

Enroll in electronic invoicing with Marsh & McLennan partner Tungsten:

Electronic invoicing with Marsh & McLennan is currently live for Marsh & McLennan Companies, Marsh, and Guy Carpenter businesses in the United States, Canada, United Kingdom, Ireland, Sweden, Australia, and New Zealand.  Further expansion is forthcoming.

Accounts Payable Contacts

Below are the appropriate Marsh & McLennan Companies, Inc.’s Accounts Payable contacts for purchase order and invoice statuses.

Marsh & McLennan Companies, Marsh, Guy Carpenter, Stars, VOSCO, ENCON 
(All countries except for Latin America):

Mercer, Oliver Wyman Group, NERA 
(North America & EMEA):

Mercer, Oliver Wyman Group, NERA
(Australia, New Zealand, Hong Kong, Singapore):

For geographies not listed, please connect with your Marsh & McLennan Companies business contact for the appropriate contact information.

Terms & Conditions

Where a master agreement is in effect between the supplier and Marsh & McLennan Companies, Inc., or the Marsh & McLennan Companies, Inc. affiliate that is the Customer, the terms of that agreement will govern all purchase orders. In the absence of any such agreement, purchase orders will be governed by Marsh & McLennan Companies, Inc.'s standard terms and conditions, except that purchase orders for the performance of Services or delivery of Goods in each of the countries listed below will be governed by the version of Marsh & McLennan Companies, Inc.’s standard terms and conditions translated into the local language for each country respectively (click on applicable country name for translation):


Prospective Suppliers

If you are a prospective supplier and would like to be considered for future opportunities with Marsh & McLennan Companies, please complete the Marsh & McLennan Companies, Inc. Supplier Registration Form below. Your information will be preserved within our Registered Supplier Database, which is referenced by our Global Sourcing and Procurement department for future opportunities.