There’s no universal age for classic bikes as every provider has its own definition.
Some bike insurance policies will consider it a classic when the bike’s 15 years old, while others cover bikes which are 25 years or older.
There are also providers who offer ‘future classic’ policies for younger motorbikes that are maintained with an eye to becoming a classic in the future.
Regardless of its age, you can cover a classic motorbike with a standard motorbike insurance or opt for a specialist policy.