When it became clear that my mother in law was slowly losing her ability to cope with life the legal work was done but it was not fully implemented for some time afterwards.

To start off with my husband simply saw that the bills were paid and stopped the people who were calling and getting her to change her gas and electric supplier, which were so many that they were queued up waiting to take over as soon as it was allowed.
The paperwork did have to be sent several times to some organisations as they lost it or had no record of it being sent - they demanded to speak to the poor woman in her bewildered state before they would accept that she was non compos mentis.

Eventually the house had to be emptied and sold after she went into a home, and now all her money is gradually being paid out for her care. It is sad, but at least her finances are arranged so as to provide for her.