Do multi-SSID Access Points need different channels?

Access Points that have multiple SSIDs assigned by nature cannot be on different channels.

Access Points that have multiple SSIDs assigned by nature cannot be on different channels.  Since they are all using the same radio, the SSIDs are taking turns and not causing interference with each other. 

So while using WiFi Scanner, many SSIDs can be shown as being on the same channel, but are actually broadcasted by the same Access Point.

An easy check is to compare the BSSIDs, they should be identical except for the last digit, which is usually one off from the other.