In one sentence: an ESC is the certificate the electrician issues — within 20 working days of the work being connected to a power supply — declaring the installation is safe to use. The CoC certifies the work; the ESC certifies the installation is safe to energise and use.
An Electrical Safety Certificate (ESC) is issued under regulation 74A of the Electricity (Safety) Regulations 2010 whenever prescribed electrical work (PEW) on an installation, part installation, or the fittings supplying one is connected to a power supply. It records that the person who did the work is satisfied the installation is electrically safe, complies with the regulations, and — where the work was maintenance, an alteration or an addition — hasn't adversely affected any other part of the installation.
It also carries weight beyond electrical law: for the purposes of section 19(1)(e) of the Building Act 2004, an ESC is accepted as confirmation that the prescribed electrical work complies with the building code.
You'll sometimes see it miscalled an "Energy Safety Certificate" — same document, but Electrical Safety Certificate is the official name used by the regulations and the EWRB.
Like-for-like replacement of fittings, relocating switches or socket-outlets on an existing circuit. Generally requires an ESC only — no CoC.
New circuits, additions and alterations — most everyday installation work. Requires a CoC + ESC. The CoC certifies the work complies with AS/NZS 3000; the ESC certifies the installation is safe to use once livened.
Mains work, hazardous areas, medical locations and the like. Requires a CoC + Record of Inspection (RoI) + ESC. The RoI comes from an independent licensed inspector before the work can be considered complete.
Full detail on the CoC side — required content, the 20-day rule, digital signing — is in EWRB CoC explained.
The person who completed the work issues the ESC — as soon as practicable after the work is connected to a power supply, and within 20 working days (regulation 74C). The certificate is given to the person the work was done for.
One trap for supervisors: a trainee cannot issue an ESC by themselves. The supervising licensed worker must date and sign the certificate and include their own registration number (regulation 74A(3)(f)(ii)) — the same liability position as certifying supervised work on a CoC.
The regulations don't prescribe a fixed form — paper or digital are both fine — but the certificate must identify the installation and the work, name the person who carried it out (with registration details), declare the installation safe to use, and be signed and dated. In practice an ESC records:
WireWrite's ESC wizard enforces each field at issue time and links the ESC to its parent CoC where one exists, so the paperwork for a job stays together.
WireWrite produces EWRB-compliant digital ESCs alongside CoCs, RoIs and CoVs. Your registration details auto-fill from your profile, your digital signature is applied on issue, and the finished PDF is emailed to the client and archived in your dashboard.
The CoC certifies the work complies with the standards; the ESC certifies the installation is safe to use once connected to a power supply. General-risk work needs both. Low-risk work generally needs only an ESC. High-risk work needs a CoC, an independent Record of Inspection, and an ESC.
Electrical Safety Certificate — that's the name in the Electricity (Safety) Regulations 2010 and what the EWRB uses. "Energy Safety Certificate" is a widespread miscoining for the same document.
As soon as practicable after the work is connected to a power supply, and within 20 working days (regulation 74C).
Not by themselves. The supervising licensed worker must sign and date the certificate and include their own registration number — regulation 74A(3)(f)(ii).
No fixed form is prescribed — the content matters, not the layout. WireWrite generates compliant digital ESCs with your details auto-filled and a locked signature, from $5/seat/month + GST; you can try the wizard free without signing up.
An ESC certifies an installation is safe to use once connected to power — required under reg 74A for prescribed electrical work. ESC vs CoC, who issues one, and the 20-day rule.