What EV Work Independents Can Do Safely and Legally
Understand the boundaries for independent garages. What you can do without high-voltage certification and when you need it.
EVs and hybrids have high-voltage (HV) systems that can be lethal if handled wrongly. That doesn’t mean independents can’t work on them—much routine work (tyres, brakes, 12V, fluids, suspension, MOT) is the same as ICE. The boundaries are: what needs HV isolation and certification, and what doesn’t. This guide summarises what you can do safely and legally, and when you must stop or refer.
Safety first
1. Work that doesn’t need HV certification
Tyres, brakes (excluding regenerative braking calibration in some cases), 12V battery, cabin filters, wipers, lights, suspension, steering, wheels, and general MOT-related checks and repairs are often the same as ICE. So long as you’re not disconnecting or exposing HV cables or components, you’re in familiar territory. You still need to know where HV parts are (e.g. orange cables, HV battery location) so you don’t damage them. Basic awareness training (e.g. IMI Level 2) helps.
2. Work that needs HV awareness (Level 2) or more
Once you’re removing undertrays that expose HV wiring, disconnecting 12V in a way that might affect HV isolation, or doing any work that could bring you near live HV, you need at least Level 2 (awareness and safe isolation). For HV diagnostics, battery testing, fault codes on HV systems, or replacing HV components, you need Level 3 (or equivalent). Insurers and warranty schemes often require proof of qualification before they’ll cover that work.
3. What to do if the fault is HV-related
If the customer’s complaint or fault code points to the HV battery, inverter, or charging system, and you’re not qualified to work on it, say so. "This looks like a high-voltage system fault—we’re not equipped to do that here. We’d recommend [main dealer / accredited EV specialist]." Don’t guess or attempt HV work without training. See how to get EV and hybrid training and certification for how to build capability.
4. Health checks and diagnostics
Battery and EV health checks (e.g. state of health, range assessment) often use manufacturer or aftermarket tools. Some can be done with OBD/diagnostic equipment and the right software; others need specialist access. If you offer health checks, make sure you’re trained and insured for what you’re doing—and be clear with the customer what the check does and doesn’t cover. See how to start offering battery and EV health checks.