After the 1987 hurricane, my Dad's claim made under his Sun Alliance buildings insurance policy for significant storm damage to his house and garage was repeatedly stonewalled by the insurer. His double garage had been smashed by a fallen tree. In total 18 trees fell in his garden. Flying pine needles had stripped all the exterior paint on one side of the house. Window frames were blown inwards and glazing smashed. Roof tiles lost and guttering damaged. A big claim.The way that reinsurance has always, traditionally, worked in the UK (and let's not forget that Lloyd of London was also in the past the 'natural base' of insurers worldwide to provide that cover to their customers also worldwide) is that insurers have always 'laid off' some huge risks to those outlets, all quietly and efficiently completely unseen by the average man in the street insuring his whatever Bloggs and Co on the High Street. If he gets as far as the small print there will be info saying he's actually insured with Aviva or Sun Alliance etc etc. However the terms and conditions that those reinsurers apply to each contract can and will be different for each insurer. Head Office Finance function and not even apparent to those in the front offices. So the cover might only kick in when that insurer's cumulative claims for fire, flood, theft, volcanic eruption or Tsunami or whatever specific cause exceed several million or even several billion. I have no experience whatsoever of members of the public or a UK registered UK company or charity being able to approach a reinsurer themselves for insurance.
But I've now been retired from the industry (which always was more than 'a bit' er, incestuous might be an appropriate word or might not) since 1998 so simply no longer know what's currently what.
I had to get "legal" on his behalf to make them drop the excuses and agree to pay. My Dad later found out that Sun Alliance had decided not to reinsure their storm claim risks and therefore got caught with their pants down by that exceptionally violent storm.