[Glassy80]

I bought my iPhone from eBay and even though the unlock procedure went through fine, no sim cards allow me to make/recieve calls. I'm thinking it could be barred as it might have been stolen or lost?

Is there anyway of finding this out using my IMEI number? If it is, what can I do?

I imagine if it is barred that it will be the IMEI number thats barred. Can this be changed? I imagine its the same as a MAC address on a piece of hardware, which can be changed.

[cpjr]

It cant be changed. If it was barred, it would only matter on ATT. You can call ATT and they can confirm if it is.