In the US I experienced the opposite. I broke a finger while moving to a new city and transitioning coverage. It needed surgery, so I got it done under my old policy, after I’d gotten to the new state.
It took them, no shit, two years to figure out there was an issue with the billing and start demanding money, by which time I’d changed jobs and had to change coverage again. As far as they knew I was uninsured for the surgery, and they sent me a total bill for around $6,000.
I talked to the assorted insurance companies to figure out who was responsible for covering it, got that sorted out, and later found they submitted a bill to the insurance company for $30,000, of which I ended up owing… around $6,000. The insurance did me zero net good. It just gave the hospital a chance to double-dip for way more money.
I’m fairly sure that has to be illegal. It sounds very much like a kind of insurance fraud to me, but I had too much else going at the time to follow up, and I just bet I was under a mandatory arbitration clause anyway.
