If you don't make any claims on your insurance during the course of your policy then you begin to build up no-claims bonus. You can build this up if you have Comprehensive, Third Party, Fire and Theft or Third Party insurance.
You could lose your no-claims bonus if you're involved in an accident with an uninsured rider or driver. This is also the case if your bike is stolen, and you have to make a claim on your insurance.
Some insurers might ask you for proof of your no-claims bonus - you should be able to get this from your previous or current insurer. You should have the option to pay extra to protect or guarantee it. The terms of these extras can vary between insurers, so check your policy before buying.