I have a moderately good insurance policy through work, but I don't think it would see me very well through a really major accident or major health emergency like an extended bout of cancer, etc. Are there supplementary coverage options to add to this? How do I handle the issue where one insurance company is the 'main' one and the other is the 'supplementary' one?

That's exactly what I asked in my "Double insurance" post, check that out as well. Looking forward to seeing the replies here, maybe you get more of them.

check out william russell

I am in the same situation as you. I have a ok-ish local plan through work, and the William Russell bronze plan, for exactly type of situations you describe. Sets me back around $80 a month from memory, so not too bad. You'll find them much better value than any local 'high end' cover from NZI etc.

We've had to use them a couple of times in an emergency, and they've been great. Wife had to fly back to NZ on the death of her brother, all covered.

I was admitted to hospital for the day with severe dehyration from the stomach bug from hel_l a few weeks back. Samtivej's 18,000 bill was all covered, something my local Bupa wouldn't have.

I use the local Bupa if I've got the flu, etc and need to see the doctor. Anything that requires in-patient treatment, William Russell.