You could simply buy a Eurail Pass, it's not cheaper and it wouldn't have a 2-day restriction in the UK.

If you are travelling to Switzerland by train (which I'd really recommend, just did that journey last month), book Eurostar seat reservations early (they can sell out weeks in advance) : 30€.

TGV Lyria (direct into Switzerland) has a very expensive seat reservation fee (more than 30€). But you can save money by taking the TGV only within France (Strasbourg/Bellegarde/Mulhouse) and then a regional train. The TGV to Strasbourg is usually the best as it departs from Paris-Est (and not Gare de Lyon) and then the TER regional trains run at 200 km/h :)

Thanks for the suggestions.

Bit more background on my trip is that I am already flying into Geneva, and out of Zurich.

So my question is to do with domestic travel within Switzerland using Interrail as resident in the UK, but not a citizen. Not how to get to Switzerland from London.

Want to make sure I do not get caught out on a technicality.

Any info on that would be appreciated.

Thanks

For travel in Switzerland, it doesn't make a difference whether you have Interrail or Eurail. You can also use both to get to a UK airport.

Not sure if you’ve understand the initial question correctly.

im looking for a Yes / No answer - whether as a resident living in the UK, (but not a citizen) i am eligible to purchase an Interrail pass.

That’s it. Thanks

Yes you are, as long as you can show some official document that you live in the UK.

And it has to be a physical document, an electronic document is not valid.