Who makes the profit when one trust charges another?

@article{Harrison2008WhoMT,
  title={Who makes the profit when one trust charges another?},
  author={Malcolm C. Harrison},
  journal={Nursing standard (Royal College of Nursing (Great Britain) : 1987)},
  year={2008},
  volume={23 3},
  pages={32}
}
On the subject of car parking fees (news September 10), when staff working for primary care trusts visit secondary care trusts as part of their job, the primary trust has to pay parking charges. How silly is that?