A middleman, sometimes referred to as a gateway provider, is considered a third-party intermediary in payment processing, such as: Independent sales organizations (ISOs) Non-processing banks Resellers that sell payment processing, POS systems, and other services to their business owner clients. Enterprise software companies Accounting firms IP gateway vendors Salespeople Referral groups Middlemen may add their own fees, making money off of each transaction, which can be a drain on your revenue. However, in some cases, they provide a necessary service for your business. Getting rid of middlemen may require changing other vendors in your technology stack, so it’s important to understand the cost/benefit equation when evaluating your service providers.