“Annually” is the answer most people have heard, and for a lot of equipment it is simply wrong — sometimes too often, sometimes nowhere near often enough.
Intervals are risk-based, not calendar-based
The IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment sets suggested intervals according to the type of equipment and the environment it lives in. A desktop computer that sits untouched on a desk in a clean office is in a fundamentally different risk category from a handheld drill on a construction site, and treating them identically wastes money on one and endangers people with the other.
The factors that move the interval
- Environment. Dust, moisture, heat and vibration all accelerate deterioration. A commercial kitchen is harder on equipment than a meeting room.
- How the equipment is used. Moved daily, or installed once and left? Handheld equipment flexes its cable at the entry point constantly — the most common failure point we see.
- Who uses it. Equipment used by the public, by children, or by staff with no electrical awareness warrants closer attention.
- Appliance class. Class I equipment relies on an earth connection to be safe, so a fault matters more than in double-insulated Class II equipment.
- Failure history. If a particular category keeps failing, shorten its interval. If nothing has failed in three cycles, you may be able to extend it.
Rough guidance by setting
As a general shape — and this is guidance, not a substitute for assessing your own premises:
- Offices, shops and hotels: stationary and IT equipment is often on a long cycle of 24–48 months, with a formal visual inspection in between. Handheld items such as kettles and vacuum cleaners come round sooner.
- Commercial kitchens and hospitality: considerably shorter, typically annually, because heat, steam and constant movement take their toll.
- Schools and colleges: annually for most portable items, aligned to term breaks so nothing disrupts teaching.
- Construction and industrial sites: months rather than years for 110V handheld tools.
- Let residential property: commonly tied to the tenancy cycle or the property’s wider electrical inspection.
Visual inspection carries more weight than people think
A large share of faults are found by looking, not testing: a nicked flex, a cracked casing, scorch marks around a plug pin, a cable pulled out of its grip. Formal visual inspections between full tests are quick, cheap, and catch most of what matters. Train someone on site to do them and record the result.
Write the interval down, and justify it
The most common failing we encounter is not the wrong interval — it is an interval nobody can explain. Record what you chose and why. If an inspector asks, “every 24 months, because this is a low-risk office environment and we have had no Class I failures in two cycles” is a defensible answer.
We assess your premises and recommend an interval you can stand behind, then remind you before it falls due. Ask us what yours should be.