I've had contents insurance with Liberty Insurance now for 6 years and never made a claim. Can I use those years as No Claims Discount when buying home insurance for a house I'm purchasing?
That's why they normally ask if/when you've had claims - to determine the no claims discount on the base policy premium.
Whether or not contents only (rental tenant I presume?) no claims will transfer to a buildings/contents owner occupier policy depends on the broker/underwriter and you'd need to ask them.
Similar to pet insurance. Always ring and ask Allianz for discount on pet insurance renewal and maybe get 10% off. One year because there had been claims no discount allowed.