[LinuxBender]

You probably won't need to ring your ISP unless you are unable to request a new IP through your router. If its a consumer router then there may be a UI that allows you to "release" and "renew" your IP on the WAN interface, maybe. You may end up with the same IP. Google your router make and model to get more details. You've got everything else right.

[jojojaf]

Oh I didn't realise I could just do that myself.

Well, thank you so much for all of your help