An 
online business payment method that provides credit and cash 
flow management for at least one seller of products or services, at least one buyer of the products or services, and a financial institution via a business 
payment system accessible via a 
network connection. The method includes first establishing a 
credit line for the buyer by the financial institution. Next, placing a 
purchase order for a product or service by the buyer to the seller and entering a 
purchase order number into the business 
payment system. Next, accepting the 
purchase order by the seller and providing the product or service to the buyer. Next, sending an 
invoice by the seller to the buyer and entering the 
invoice into the business 
payment system against the purchase 
order number. Next, approving the 
invoice by the buyer, entering the approval into the business 
payment system and notifying the financial institution of the approved invoice by the business 
payment system. Finally, approving payment of the approved invoice by the financial institution and paying the invoice by transferring money from the buyer's 
credit line to an account of the seller. The seller sets a payment term for the invoice and pays a seller's fee to the financial institution upon 
receipt of the invoice payment. The seller's fee depends upon the invoice payment term. The buyer pays interest to the financial institution when the invoice payment term is not met. Access to the 
online business payment 
system is secure and selective access permissions are defined for each member.