A method for placing concurrent holds, wherein a first client device, a second client device, a communication system and a content delivery service are connected through a communication network, and are configured to communicate with each other through use of the communication network; the method comprising, by the communication system: receiving, from the first client device, a first hold command to place a first hold on a first communication session between the first client device and the second client device; allocating a first unique identifier to the first hold; initiating a second communication session between the second client device and the content delivery service, the content delivery service providing content to the second client device via the second communication session during the first hold; updating a first record associated with the first unique identifier to include data identifying the second communication session; providing the first unique identifier to the first client device, the unique identifier enabling the first client device to reference the first hold; and terminating the first communication session; characterized in that the method further comprises: receiving, from the second client device, a second hold command to place a second hold on the second communication session between the second client device and the content delivery service; allocating a second unique identifier to the second hold; updating the first record associated with the first unique identifier to include an indication that the first client device is to be placed on hold when the first hold is ended; updating a second record associated with the second unique identifier to include an indication that the second client device is to be placed on hold when the second hold is ended; returning the second unique identifier to the second client device, the second unique identifier enabling the second client device to reference the second hold; and terminating the second communication session. receiving, from the first client device, a first hold command to place a first hold on a first communication session between the first client device and the second client device; allocating a first unique identifier to the first hold; initiating a second communication session between the second client device and the content delivery service, the content delivery service providing content to the second client device via the second communication session during the first hold; updating a first record associated with the first unique identifier to include data identifying the second communication session; providing the first unique identifier to the first client device, the unique identifier enabling the first client device to reference the first hold; and terminating the first communication session; receiving, from the second client device, a second hold command to place a second hold on the second communication session between the second client device and the content delivery service; allocating a second unique identifier to the second hold; updating the first record associated with the first unique identifier to include an indication that the first client device is to be placed on hold when the first hold is ended; updating a second record associated with the second unique identifier to include an indication that the second client device is to be placed on hold when the second hold is ended; returning the second unique identifier to the second client device, the second unique identifier enabling the second client device to reference the second hold; and terminating the second communication session.