Why do we have to pay for unanswered phone calls?

[#1]

I've just noticed that a call we made a couple of days ago has been charged at 22p. This call was unanswered either by the person called or any automated system.
So why do we get charged for calls that are never connected?   
I've searched for information on the website but have failed to find anything that says such calls are chargeable. Does anyone know where I might find this?

[#2]

Was this a call to a mobile? Mobile phone operators charge other phone companies for attempting to connect calls whether they are answered or not. These charges may then be passed on to the caller.

[#3]

Quote from: alanf

Was this a call to a mobile?

No, this call was to a BT landline.

[#4]

Company switchboard? I suppose you could be connected to a private exchange and hear a ringing tone while that exchange calls the extension.

[#5]

No it's simply a BT landline at a private house with the answer machine switched off.

[#6]

In that case.... not sure if this is up to date but according to Ofcom guidance....
"Call charging starts when a call is first answered. If it is not answered, there will be no charge......"
"A call is not answered, and so you do not incur any charges, if the first and only thing you hear after you have dialled the number is:
    A ringing tone, or
    An engaged tone, or
    An �out of service� announcement, or
    A number unobtainable tone, or
    An announcement that specifically says that you have not been charged (eg a changed number announcement). This could follow a ringing tone."
"What to do about charges for calls which appear to be unanswered
If you think you have been billed for calls which have not been answered you should contact the telephone company billing you for the call."
http://www.ofcom.org.uk/static/archive/oftel/consumer/advice/faqs/conguide1.htm

[#7]

@alanf Thanks for the update.
Hopefully someone from PN will respond with some clarification soon.

[#8]

We don't know about a call unless it's answered. I expect that the reason is something as simple as the answer phone cut in / someone picked up just as you were putting the handset down or the call was diverted to another number which then wasn't answered (i think that would be chargeable). Unfortunately this isn't something that we would be able to look into unless it was an endemic issue, sorry.

[#9]

Quote from: Ben

or the call was diverted to another number which then wasn't answered (i think that would be chargeable)

Yes it's chargeable but not to the caller but to the called number.

[#10]

While the 'forwarded part' of any forwarded call is charged to the called party the original call (which has 'connected' in order to be forwarded) is chargeable to the calling party.
I suspect it's as Ben suggested, the phone was answered just as the caller hung up, this costs 22p with rounding* (13.1p connection + 7.95p/minute) call cost then rounded up to the nearest penny.
*Correct for Home Phone packages taken before 8th May 2013

[#11]

Can i have the date/time of the call so I can check the un rounded duration?

[#12]

Hi Ben
The call was made on 16/08/2013 at 15:56:14.

[#13]

The un-rounded duration was 1.63 seconds so it looks like it was answered as you were putting the phone down, sorry.

[#14]

Thanks Ben.
My own investigations have revealed:
The person we were trying to contact was away on holiday.
There was a fault on her landline so BT were diverting all calls to a mobile.
The mobile did not register a missed call.
So it looks like BT were still in the process of doing the transfer whilst we were hanging up and thus terminating the call.
At least it looks like we now know what probably happened. 

[#15]

Thanks for letting us know, good to get to the source of the problem.