IBG vs manufacturer’s warranty vs company written guarantee: what’s the difference?

An Insurance Backed Guarantee, a manufacturer’s warranty and a company written guarantee cover different faults, with different claim routes. Here’s who covers what and when.
Do UK installers legally need an Insurance Backed Guarantee?

Whether you must provide an Insurance Backed Guarantee depends on your trade and scheme. Here’s the position for double glazing, renewables, roofing, bathrooms, kitchens and general building — trade by trade, in one table.
What is an Insurance Backed Guarantee (IBG)? A UK installer’s complete guide

An Insurance Backed Guarantee (IBG) is an insurance policy purchased by the installer for the homeowner. It sits with the homeowner for the duration of the policy term. If the installer goes out of business as per the policy terms, the Insurance Backed Guarantee comes into effect to honour any valid claim the installer would otherwise have met. The homeowner is the policyholder; the installer is the buyer.