On each year’s premium rate page, you can find the premium rate manual, which lists that year's premium rates and describes, with extensive supporting documentation, how we determine these rates for each rate group. These manuals are also available dating back to 2005 in the Previous rates section.
In addition, you can find the year’s premium rate estimator if available. Depending on the nature of your business activity, determining your premium can sometimes be a challenge. The premium estimator takes you through the various steps involved in calculating your premiums.