Methods and apparatus are disclosed to negotiate flow control for a communication session between peer devices. An example first peer device disclosed herein is to send a request message to a second peer device via an existing communication session that is subject to a first type of flow control, the request message to initiate a request for a second type of flow control for the existing communication session, the second type of flow control different from the first type of flow control. The disclosed example first peer device is also to change to the second type of flow control for the existing communication session in response to a reply message from the second peer device via the existing communication session, the reply message indicating acceptance of the request for the second type of flow control for the existing communication session.