DNO approval letter

Also known as DNO authorisation, DNO connection approval

A DNO approval letter is written confirmation from the DNO that an apply-to-connect installation can go ahead, sometimes with stated amendments or connection conditions.

A DNO approval letter is the written response that records a DNO has authorised a proposed connection before installation, usually after an apply-to-connect case rather than a connect-and-notify notification. In home energy paperwork it can appear around solar PV, battery storage, EV chargepoints, heat pumps or vehicle-to-grid equipment where network capacity, import demand, export capacity or Engineering Recommendation forms need to be assessed. The letter or email should be kept with the handover documents because it records the DNO decision and any amendments, export limits or connection conditions that shaped the installation. It is not a general safety certificate, planning permission, building regulations certificate, MCS certificate, export-tariff registration or approval for later equipment changes.