If there was itemised billing then one side or the other would have waved it from the rooftops at trial. I believe the exchange in deepest Essex was ancient and not able to record anymore than units used.
That is most certainly a distinct and probable possibility. So why would Mike be telling porkies?
It has been suggested that trunk calls (i.e. long distance rather than local) may have been recorded as well as international calls. I suspect operator connected calls would also have been itemised. I do not know whether the technology was available at the time for locally dialled calls to be specifically identified and timed. Whatever the position Mike's views expressed here do not amount to "porkies", they are his understanding of the position.
Ah Chelmsford telephone exchange.....
vidvic uses flowery language (hmm wonder why) to promote his belief in the relevant telephone exchange being very old and out of date for the time of the murder... nothing more than wishful thinking...how old eh vidvic in your imagination?
a little research and it cannot have been too old...for the old telephone exchange building in chelmsford went out of use in 1974....
so that immediately implies that in 1985 the replacement exchanges equipment cannot have been much older than from 1974. System X digital exchanges were being introduced in the early 80's and chelmsford is very likely to have gone to system x prior to 1985 due to its importance to BT.
Itemised billing....there are two components that are relevant... key is recording equipment to obtain the data...the paperwork side only comes later... One came before the other...so was in place before the other.
Where the right equipment was installed the ability to log calls was already present even if no itemised bills were being sent out to customers.