Just a bit further on this. A post you made on mental health day suggests the person you may wish to invite may be currently in a secure mental health setting in the states. I would really caution against expecting this person to relocate if the half expectation is he/she will be sectioned here. The stay in our facility may be more humane than they experience in the USA but the duration will be short and as a foreign national I am not sure they will qualify for community support following or free S117 after care. Given history they may well be repatriated immediately on discharge as home will be seen as more beneficial in a developed nation such as USA where they have care history .Thank you @cruze @Skandhaless @rudd @NewAdventuresInWiFi and @yorkyexile, your insight is much appreciated.
The way I am reading this is that if I invite someone from say the US, and they arrive here and feel that they are heading into a crisis, I can take them to a GP, have them go through the sectioning procedure and have them voluntarily admitted to a UK mental facility where they will get a completely new assessment. We are not sure if they would be charged money for this, but as it would be done as a legal act, it is unlikely that they would be charged.
The whole experience could be deeply damaging to such a person, please think very carefully and don't in a desire to help be tempted to be speculative using our mental health act as a fail safe, it will not be a great process.