Safety certificate (SiNa): the form, its minimum content and who must sign

The safety certificate must contain at least the addresses, a description of the installation, the inspection interval, the installer and the results of the final inspection (Art. 37 NIV). Your own form is allowed as long as it meets those requirements; an authorised person who carried out the inspection themselves must sign.

What a safety certificate is

A safety certificate (Sicherheitsnachweis, SiNa) is the document that confirms an electrical installation meets the requirements of the NIV. The ESTI publishes a form, «Sicherheitsnachweis Elektroinstallationen (SiNa)», as a PDF. When one is due and what happens if the deadline is missed is covered in «Safety certificate for electrical installations: the deadline has passed»; this article is about the document itself.

The minimum content under Art. 37 NIV

According to the ESTI's FAQ, the safety certificate must state at least:

• the address of the installation and the address of the owner,
• a description of the installation with the standards applied,
• the inspection interval,
• the name and address of the installer,
• the results of the in-house final inspection (Art. 24 NIV),
• the name and address of the holder of the inspection permit, plus the results of the acceptance and periodic inspections (Art. 35 para. 3 and Art. 36 NIV).

The technical content is set by the DETEC (Art. 37 para. 3 NIV). The details are in the DETEC ordinance (SR 734.272.3): Art. 13 governs the safety certificate, Art. 14 the measurement and test report.

Does it have to be the ESTI form?

No. A form of your own is allowed if it meets Art. 37 NIV and Arts. 13 and 14 of the DETEC ordinance. According to the ESTI, the templates from the trade associations for the safety certificate and measurement reports meet those requirements.

Measured values go in the places provided. The ESTI is explicit that the results of the checks are entered per final circuit, including the short-circuit currents Ik (L-PE) at the start and at the end and the insulation resistance Riso. What the report contains is explained in «Measurement and test report for electrical installations».

Who signs

The safety certificate must be signed by an authorised person who carried out the inspection (Art. 37 para. 2 NIV). That person must be employed by the firm whose permit number appears on the certificate.

For firms with a general installation permit (Art. 7 or 9 NIV), two people sign: the person authorised to inspect, who did the inspection, and the firm's authorised signatory. The permit holder does not have to be listed as an authorised inspector in the permit. For an independent inspection body, the inspector signs in its own box, and again the authorised signatory signs too. Names are given in block capitals.

Anyone who carried out the final inspection of an installation as an independent inspection body may not later inspect the same installation independently (Art. 31 NIV). A breach falls under Art. 42 let. c no. 6 NIV. Why independence is the heart of the matter is explained in «Commissioning an inspection body».

Photovoltaics and the restricted permit

For photovoltaic installations built by a firm with a general permit, the safety certificate under Art. 37 NIV is required together with the photovoltaic measurement and test report under ESTI directive 220.

And one sentence worth remembering: holders of a restricted installation permit (Art. 14 NIV) may not issue a safety certificate. For photovoltaic work by such firms, an acceptance inspection by an accredited inspection body is required (Art. 32 para. 2 let. b NIV).

What a firm makes of this

A certificate is only as good as the measurements under it. Three habits pay off:

1. The report belongs to the certificate, not beside it. The measurement and test report forms part of the technical content; assembling it after the inspection means copying values you can no longer trace.
2. The signatory is settled before anyone measures. Whoever inspects signs, and must be employed by the firm — that cannot be arranged afterwards.
3. Everything on the installation's file. Certificate, report and defect list in one place can be found at the next customer conversation. To place the inspections on the timeline, see «Initial verification, final inspection, acceptance inspection».

When an electrical inspection is due and who pays for it is in «Electrical inspection: duty, process and costs»; your own installation's interval is shown by the inspection interval calculator.

Common questions

Is there an official form for the safety certificate? Yes, the ESTI provides «Sicherheitsnachweis Elektroinstallationen (SiNa)» as a PDF. It is not mandatory: your own form is enough if it meets Art. 37 NIV and Arts. 13 and 14 of the DETEC ordinance.

What must the safety certificate contain? At least the addresses of the installation and the owner, a description of the installation with the standards applied, the inspection interval, the installer, the results of the final inspection, and details of the inspection-permit holder and its inspections.

Who has to sign the safety certificate? An authorised person who carried out the inspection and is employed by the firm whose permit number is on the certificate; with a general permit, the firm's authorised signatory signs too.

May a firm with a restricted permit issue a safety certificate? No. The ESTI states that holders of a restricted installation permit may not issue one.

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Source: Federal Inspectorate for Heavy Current Installations ESTI, FAQ «Periodische Kontrollen, Sicherheitsnachweise», esti.admin.ch, retrieved 18 October 2026; ESTI form «Sicherheitsnachweis Elektroinstallationen (SiNa)» (linked as a document, its layout is not reproduced). This article is not legal advice; in case of doubt, the responsible grid operator or the ESTI decides.