For a commercial business, it is the responsibility of the business owner to acquire an EPC for their premises. If they don't get an EPC for their buildings, then they could be subject to hefty fines and penalties.
If the building is being rented or sold, then it's the responsibility of either the landlord or seller to get hold of an EPC. Again, it's illegal to list any property for sale or rent without this certificate. Listing a property without an EPC will typically result in a fine of 12.5% of the property's value.
In the case that construction work is being carried out on a building, then the EPC responsibility falls on whoever is completing the work. Most commonly, this means that the construction company must provide an EPC to the owner of the building.