How often should a lightning protection system be tested?
- 2tasks
- 5sources
- checked on
- Englandscope
At least once a year. BS EN 62305 is cited by the IET and by government schools guidance as recommending inspection and testing at least every 12 months, and the trade body ATLAS advises a visual inspection every six months for critical structures.
The annual interval is well attested but the sources refer to the edition before BS EN IEC 62305:2024; the current text could not be checked.
Confirm the interval against the current edition of the standard, or with the specialist who maintains the system, before you fix it in a contract or a calendar.
What to do, and how often
| Task | How often | Who | Basis |
|---|---|---|---|
| Visual inspection and electrical test of the whole system by a lightning protection specialist | Every year | Competent lightning protection specialist | British Standard BS EN 62305 recommends that lightning protection systems are visually inspected and electrically tested at least every 12 months, as stated by the IET and by Department for Education guidance. SourcesS1S2 |
| Visual inspection between annual tests Applies to: Critical structures, as defined by the standard (for example buildings with sensitive systems or large numbers of people) | Every 6 months | Competent lightning protection specialist | Guidance ATLAS advises that buildings classed as critical structures should have the system visually inspected every six months. SourcesS3 |
Where a row says who or what it applies to, the task is for that case only.
The law
No legislation sets a test interval for lightning protection. The frequency comes from the British Standard, and following it is the usual way to show that the system has been properly maintained.
The standard
BS EN 62305 (protection against lightning). The four parts were reissued as BS EN IEC 62305:2024 and published by BSI in February 2025.
Records to keep
- Annual test and inspection certificate with earth resistance readings
- Schedule of defects and remedial work
- System drawings or a record of the conductor and earth positions
Notes
The published statements of the annual interval refer to the earlier edition of BS EN 62305.
The standard was reissued in 2024 and this dataset could not confirm from a free authoritative source that the inspection intervals are unchanged, so treat the annual figure as the established benchmark and ask your specialist to confirm it against the current edition.
ATLAS says existing systems do not need immediate changes because standards are not applied retrospectively.
Who delivers this in the group
Not a group service
This is not delivered by an AMPM Group company. It is listed because building managers need the whole picture.
Questions people ask
Lightning protection systems: is the interval set in law?
No task on this page has an interval set in legislation. Each one is recommended by a British Standard or by guidance. No legislation sets a test interval for lightning protection. The frequency comes from the British Standard, and following it is the usual way to show that the system has been properly maintained.
Lightning protection systems: who should carry out each task?
Competent lightning protection specialist: visual inspection and electrical test of the whole system by a lightning protection specialist; visual inspection between annual tests.
Lightning protection systems: what records should you keep?
Keep these records: annual test and inspection certificate with earth resistance readings; schedule of defects and remedial work; system drawings or a record of the conductor and earth positions.
Sources
Every task and legal statement is supported by at least one source fetched over HTTPS and read on the date shown. Quotes are verbatim and 25 words or fewer. A second, independent verification pass re-fetched every source and re-read the legislation on 5 October 2026. Intervals taken from British Standards were checked against published summaries of those standards by trade bodies and government guidance, because the standards themselves are paid publications.
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Lightning Protection and Foundation Earthing webinar: questions and answers ↗
Institution of Engineering and Technology (IET) · Webinar held 16 February 2021 · read on
“all systems should be visually inspected and electrically tested every 12 months as a minimum”
Supports: IET statement of the BS EN 62305 inspection and test interval
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Good estate management for schools: Health and safety ↗
Department for Education (GOV.UK) · Updated 20 July 2026. Written for schools · read on
“recommends that all lightning protection systems are inspected and tested at least annually”
Supports: Government schools guidance on the BS EN 62305 interval
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Inspect and Protect campaign ↗
Association of Technical Lightning and Access Specialists (ATLAS) · Page as shown on 5 October 2026 · read on
“should have their lightning protection system visually inspected every six months with electrical testing performed once a year”
Supports: ATLAS: six-monthly visual inspection and annual electrical test for critical structures
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International lightning protection standard BS EN IEC 62305 updated ↗
Association of Technical Lightning and Access Specialists (ATLAS) · Published 25 February 2025 · read on
“BSI published the updated UK lightning protection standards”
Supports: The standard was reissued as BS EN IEC 62305:2024
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International lightning protection standard BS EN IEC 62305 updated ↗
Association of Technical Lightning and Access Specialists (ATLAS) · Published 25 February 2025 · read on
“Standards are not applied retrospectively, so existing lightning protection systems do not require any immediate changes.”
Supports: Existing systems do not need immediate changes