Question:
I am looking for a recommendation on a conference call service for a small team (7) of home workers based in the UK.

Most calls and clients will be within the UK We would like clients to be able to dial in, or allow us to dial out to clients We will have a small call  volume 1 or 2 calls per week (120min) A permanent conference would be preferred - I hope that make sense

I look forward to recommendations and / or warnings about any services to avoid.

Answer:
You get allocated the numbers on a permanent basis. This facility is based on either 0844 or 0870 access. A maximum of 120 people can dial into this service for training etc.  0870 would be used if there was international required other wise 0844 gives every one a local access at daytime rates 24/7. Chair and participants are on different numbers

The Chairman of the Conference call has web access to see how many people have logged and has a mute facility to prevent interruption which can then be opened up for questions and discussion etc.

Then there is a revenue share option on 0870 numbers @ £200 PA

Mind you, you do say that you require seven people in the conference call. Orange allow five  (plus you, the caller, which makes six). So if you can work with six parties (and manage to get just one of them to share a connection  or just one of them to use ANOTHER  Orange OVP Virgin Sim card; also in a conference call) then you can do the whole lot for 5p/min to each party (ok ..so the first five minutes are at 15p/min but that's just to one party .the rest will be at 5p/min so you can safely discount that when you consider the overall cost). That beats a  0870 number hands down during office hours.

I would say that three may be better either for dialing the 0870 as they don't appear to be charging or just direct dialing you can have 5 parties I believe (have one party as  the 0870 if you need more).

 The 0870 suggested appears to be the cheapest otherwise, 0871 and 070 numbers are used by similar services.