Just to confirm how easy it was to make this change. I telephoned BT, got through almost straight away - ensure that you get a real person to speak to. Told them I was with BT with a contract that had more than a year to run. Asked about the Essentials Package, explaining that I was on Pension Credit.
Young lady went through the details,, checked my existing account, and confirmed it would be much cheaper on Home Essentials. When I said I wished to continue with this, she transferred me (took less than two minutes), to another department where they took my NIH No. and checked that I was actually in receipt of PC. And then it all went ahead to make the new arrangements.
My bill - at present just over £31 each month - will drop to £15 per month for my BB and Land Line, still with free calls, etc. They have also confirmed that if I transfer my mobile phone over to the (EE) that will cost me slightly less than I am paying at present with O2.
Both were extremely charming and totally helpful. Took me about 15 minutes to do this. One of the best 15 minutes I have spent.