Hello Bruce Ramsay,
Thanks for your question
If you have access to the portal, go to Azure Cost Management + Billing portaland check if your email is listed under Billing administrators. If listed, request the account owner to remove you.
If you do not have access to the account but still receive invoices, submit a request to Microsoft via https://azure.microsoft.com/en-us/support/create-ticket
Billing tickets are free. Select Billing and request assistance
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola