There are several types of payment IVR. Each of these types of Payment IVR have uses, however, certain IVRs have much better customer experience than others.
This is an automated environment whereby the caller is directed through the contact centre system to a payment application. The customer can pay for services through speech recognition and keypad tones. There is no human interaction.
In this situation, the customer engages with an agent. At as result of this conversation, the customer needs (or wishes to) make a payment. The agent then sends the customer into a payment IVR. The agent is now no longer involved in the call and is free to talk to other customers. The customer completes the payment process and ends the call. This is sometimes called "fire and forget".
The issue with this is process is that the customer may choose not to complete the payment process or perhaps get stuck and not be able to proceed. As the customer cannot get back to the agent, they will have no choice but to drop the call. While it is possible that they absolutely want to make the payment and will call back and persist it is more likely that they give up and a sale is lost. Or, in the case of debt collection, the opportunity to collect is lost and considerable effort needs to be made to contact the customer again.
In this situation the agent remains on the call with the customer. However, during the payment process, the customer is sent into a secure payment system where they will enter their card details via their phone keypad. The agent remains on the call and is able to monitor its progress through the payment process. The Agent can also break into the call, if it looks like the customer is in difficulty. Also, the customer is able to return to the agent as necessary.
The issue with this method is that the agent is exposed to the DTMF tones tapped into the keypad and it is possible to translate these tones into numbers and copy the credit card number. The result is that any agent assisted solution needs to find a way to not expose the agent to these DTMF tones, if it wants to be PCI-DSS compliant. The traditional way to do this is through DTMF tone suppression, but this technology is presently expensive and may involve the installation of hardware or routing your calls through your payment IVR provider.