Yes, you surely can avail the NCB if you change your insurance provider at the time of renewing the policy. All you would need to do is producing a proof of the earned NCB from your current insurance provider. You can produce the original copy of your expiring policy and a certification that you haven’t filed any claim for the (expiring) insurance plan. A renewal notice or a letter stating that you’re entitled to the NCB from your previous insurance provider can be a proof for this.
Comprehensive insurance covers all of the above and damage to the vehicle caused by the driver themselves, as well as vandalism and other risks. This is usually the most expensive type of insurance. It is custom in the UK for insurance customers to refer to their Comprehensive Insurance as "Fully Comprehensive" or popularly, "Fully Comp". This is a tautology as the word 'Comprehensive' means full.
In South Australia, since July 2016, CTP is no longer provided by the Motor Accident Commission.The government has now licensed four private insurers - AAMI, Allianz, QBE and SGIC, to offer CTP insurance SA. The scheme allocates one provider for 3 years as part of vehicle registration. After July 2019, vehicle owners can choose a different CTP insurer and new insurers may also enter the market. 
More commonly purchased is third party, fire and theft. This covers all third party liabilities and also covers the vehicle owner against the destruction of the vehicle by fire (whether malicious or due to a vehicle fault) and theft of the insured vehicle. It may or may not cover vandalism. This kind of insurance and the two preceding types do not cover damage to the vehicle caused by the driver or other hazards.
A compulsory car insurance scheme was first introduced in the United Kingdom with the Road Traffic Act 1930. This ensured that all vehicle owners and drivers had to be insured for their liability for injury or death to third parties whilst their vehicle was being used on a public road. Germany enacted similar legislation in 1939 called the "Act on the Implementation of Compulsory Insurance for Motor Vehicle Owners."
As with any credit check, a record of this search will remain on your file – and your credit rating will affect the amount of APR that you’re charged. If you have a poor credit rating, you may be charged up to 20% APR. And if you’ve struggled to pay credit in the past, or if you have a CCJ to your name, then you may be denied the option to pay monthly. If you think you’ll have issues with your credit rating, you can read our guide on improving your credit score.
Auto insurance is financial protection, and not just for the investment you made when you bought your car. After a really serious accident, bills for damage and injuries can easily reach into hundreds of thousands of dollars. If you happen to cause such a wreck, the victims could sue you. In the worst case scenario, assets such as your savings and home could be seized.