How is my bill calculated?

Calculating Business Rates (Non-Domestic Rates)
Every non-domestic property, unless exempt from Business Rates, has a Rateable Value (RV). Each year the Government sets a fixed amount to be used in calculating Business Rates. This is known as the multiplier. Your bill is calculated by multiplying the RV of the property by the appropriate multiplier.

Rateable Value (RV)
The RV is assessed by the Valuation Office Agency (VOA), which is an agency of HM Revenues and Customs.  The RV broadly represents the yearly rent the property could be let for on the open market on a particular date. The RV may also alter if the circumstances of the property have changed.

The Government sets two multipliers every year - the standard multiplier and one for small businesses.