Yes it is possible to transfer your existing Virgin Media number to another provider. You would need to mention this to your new provider as they would need to put the transfer order in to us. We will receive an order from your new operator and check to make sure all the details are correct and approve the order. The process when we transfer numbers in usually takes around 7 to 10 days to be completed but this would usually be setup to coincide with your install date to avoid any crossover periods and any confusion.
Please don't ask for this number to be disconnected with us as the number transfer can only take place with an active working line, if the number is disconnected the transfer wont be able to take place.