sorry that i didnt reply earlier, i was offline for some days. And our company LAN has xxsim.com blocked. haha
i can confirm it is a +4477003 number assigned.

The wholesale termination rate to Jersey is 4.11 pence a minute at the moment.

There have been proposals to reduce it in about 3 stages to close to the UK rate of 0.49 pence a minute, but these haven't yet been enacted. Some more consultations and announcements on the way, perhaps.

Isle of Man mobiles currently 1.25 pence a minute wholesale, already there for a couple of years, and continued at the last review.

Perhaps as these rates drop, the possibilities for using the incoming rate to subsidise cheap or free roaming may also recede, unless networks all over the world start reducing rates too.