What happens during a PAT test?

Before we arrive

A useful visit starts with a clear appliance count and access. Have plugs reachable — not buried behind filing cabinets or locked cupboards. If you have a previous register, share it; it speeds up labelling and helps spot items that missed the last cycle.

For holiday lets and rentals, we usually test everything you supply: kitchen kit, lamps, vacuum, iron, and any extension leads left for guest use. Offices: desk equipment, kitchen, communal areas, and any extension leads in regular use.

Step 1 — User checks (ongoing, not just on test day)

User checks are quick looks before use: damaged flex, loose plug, scorch marks, cracked casing. Staff or cleaners can do these between formal visits. Problems found should be reported and the item taken out of service — no record needed unless something is wrong.

Many real-world hazards are caught here before any test instrument is opened. That is why we encourage clients to treat visual checks as part of normal housekeeping, not something that only happens when the tester visits.

Step 2 — Formal visual inspection

The tester examines each item systematically: correct fuse type and rating, cable grip secure, no taped joints, plug pins straight, enclosure intact, suitability for the environment (kitchen, workshop, outdoor use), and signs of overheating. Counterfeit or non-UK plugs are flagged.

A large share of failures are visual-only — the appliance never reaches the electrical tests because it is already unsafe. Failed items are labelled, removed from service, and recorded with the reason.

Step 3 — Electrical tests (where applicable)

For Class I appliances, earth continuity confirms the protective conductor path is intact. Insulation resistance (typically 500 V DC, or 250 V / alternative leakage on sensitive IT kit) checks that live parts cannot reach surfaces you touch. Class II items skip earth continuity but still receive insulation or leakage checks where appropriate.

Extension leads and IEC leads are tested as items in their own right — polarity and wiring matter. RCD-equipped leads may receive an operational trip check. Finally, a functional check confirms the appliance switches on and operates normally. Tests follow a safe sequence; insulation is checked before any test that applies mains voltage.

Step 4 — Labelling and records

Passed items receive a durable pass label with a unique ID, test date, and tester identification — not usually a “retest due” date on the label itself (the IET Code of Practice recommends managing intervals in your records instead). Failures are clearly marked and listed separately.

You receive a certificate and an itemised register: appliance ID, description, location, class, result, and notes. On Test Harbour, that lives in your dashboard with retest reminders — so the visit is not the end of the story.

How long it takes

Most items take one to three minutes including visual checks and labelling. A furnished holiday let with around twenty appliances is often under an hour. A busy office with seventy items might take two to three hours depending on access and floor layout. We work floor-by-floor to minimise disruption.

Quick answers

Relevant services & areas

Booking or compliance questions for your premises? These pages go deeper on what we test locally.