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Accounts payable

Discover the systems that Ontario Power Generation uses to communicate with vendors and suppliers to ensure invoices and payments are addressed efficiently and accurately.


We encourage all suppliers to please refer to your purchase order for invoicing instructions.

Vendors submitting invoices to OPG are required to use the Ariba Network. For help submitting your invoice using Ariba, please contact

Note: OPG automatically does not accept invoices for purchase orders that do not require an invoice for payment.

Please refer to the Electronic Commerce FAQs for additional information.

Electronic payment and remittance

For Canadian suppliers, this is referred to as electronic funds transfer (EFT) and automated clearing house (ACH) for U.S. supplier invoice payments.

Invoice payments will be made directly to the supplier's bank account. This process reduces the time required for suppliers to receive their payment by eliminating mail and deposit time.

In addition to electronic payment, we also use electronic remittances. OPG will provide payment details to you via fax, email or the bank’s EDI 820 message.

Questions about accounts payable?

The Accounts Payable department can answer your questions about purchase order related invoices, tax information, or other accounts payable issues.

The AP Help Desk is available to answer your questions by email or voicemail, Monday to Friday, 8 am to 3 pm EST. Be sure to include your purchase order, invoice number, and contact information at

Toronto area: 416-592-4005
Toll-free: 1-888-264-3460

Note: The AP Help Desk does not assist with inquiries regarding payment status – please visit the Invoice Query section for status inquiries.

Accounts Payable Electronic Funds Transfer Registration/Change/Cancel