In the UK, business energy customers are generally categorized as Micro-Business, Small Business (SME), and Medium/Large (Corporate) based on factors like energy consumption (kWh Usage), employee head-count, and £ turnover / year.
Specific criteria for each category can be found on the Ofgem website. Elaboration:
Micro Businesses
Small Businesse
Medium and Large Businesses
These are businesses that use less than 100,000 kWh of electricity per year or less than 293,000 kWh of gas per year,
or they have fewer than 10 employees and an annual turnover not exceeding £1.716 million.
A business with fewer than 50 employees or their full-time equivalent, and an annual turnover of at most £6.5 million or a balance sheet total of no more than £5.0 million is considered a Small Business.
They are also considered a Small Business if they use no more than 200,000 kWh of electricity per year or 500,000 kWh of gas per year.
These are generally businesses that don’t fall under the Micro or Small Business definitions, often having larger energy
consumption, more employees, and higher turnover.