An EPC is valid for ten years from the date it is issued. A new EPC is not required each time there is a change in tenancy, or when the property is sold, as long as the EPC is no more than ten years old.
An owner, landlord or tenant can commission a new EPC within the ten-year period which will then replace the earlier EPC and become the current EPC for that property.
Once an EPC reaches the ten-year expiry date, there is no automatic requirement for a new one to be commissioned. A further EPC is only needed when a 'trigger point' is reached. A 'trigger point' can be when the property is next sold, let to a new tenant or substantially modified.
As the EPC relates to the property, rather than the owner, it will remain valid even after the property is sold on to a new owner, as long as it is less than ten years old.