Not sure- but I suppose it must be the rules and regs re the Association who would provide support. Dignitas is realtively accessible. BTW Dignitas had a nice flat where people could go and die with their help. But residents' complaints meant that they had to move to an industrial estate, to a concrete block. The inside has been made as welcoming and 'warm' as can be- but it is a shame.
As a member of EXIT, I would be able (and OH too), should I ever wish it, to die in my own home, and even in my garden as it is very private. EXIT is for anyone who is resident in Switzerland, irrespective of nationality. As a long term member, they have told me that, should we ever return to live in UK, as long as we keep a property here, rented or owned and of whatever size- they would agree to assist there.
Many friends and relatives in the UK have asked us if we would be prepared to host them- if ever they were in need - but that would not be possible, unless they became resident for at least 6 months to 1 year.