How Often Should You Review a Risk Assessment? A Practical Guide for UK Tradespeople
If you've ever wondered how often you should review a risk assessment, you're not alone. It's one of the most common questions tradespeople ask — and the honest answer is that UK law doesn't set a fixed interval. What it does set is a clear duty to keep assessments "up to date".
Under Regulation 3 of the Management of Health and Safety at Work Regulations 1999, employers and the self-employed must carry out a suitable and sufficient risk assessment and review it when there is reason to believe it is no longer valid. That's the legal baseline. Everything else flows from it.
What Does "No Longer Valid" Mean in Practice?
An assessment becomes invalid when the assumptions it was built on change. That could mean a change to:
- the task or method of working
- the people doing the work (new starters, younger workers, pregnant workers)
- the materials or substances used
- the site layout or environment
- the equipment or plant involved
- relevant legislation, an Approved Code of Practice, or HSE guidance
If any of these shift, you must revisit the assessment — not wait for your next scheduled review.
Trigger-Based Reviews vs. Time-Based Reviews
The law is trigger-based, not calendar-based. However, most sensible businesses use both approaches together.
| Approach | When it applies |
|---|---|
| Trigger review | After an accident, near miss, complaint, or any significant change |
| Periodic review | On a regular schedule, regardless of changes, as a safety net |
Relying purely on triggers means you might miss gradual drift — small changes that individually seem minor but collectively make your original assessment out of date. A periodic check catches that.
What Interval Is Reasonable?
Because the law doesn't prescribe a timeframe, you must judge what's appropriate based on risk level and rate of change.
High-risk or fast-changing work — working at height, confined spaces, hot works, complex multi-trade sites — warrants review at least every 6 to 12 months, and often at the start of each new phase or project.
Lower-risk, routine work — basic plumbing in an unoccupied domestic property, for example — might reasonably be reviewed every 1 to 3 years, provided nothing has changed.
A sensible rule of thumb used widely in industry: review every 12 months as a minimum, and immediately after any significant change or incident. Many principal contractors and clients write this expectation into their contracts, so it's worth knowing even if you're a sole trader.
Situations That Should Trigger an Immediate Review
Don't wait for your scheduled date if any of the following occur:
- An accident or dangerous occurrence — even if no one was hurt, it signals a gap in your controls
- A near miss — treat it as a warning, not good luck
- A change in work scope — new tasks, materials, or locations not covered by the original assessment
- New workers on the job — especially inexperienced operatives, apprentices, or anyone with a health condition relevant to the risks
- New or updated legislation or HSE guidance — your assessment must reflect current requirements
- Feedback from workers — operatives on the tools often spot hazards the assessment missed
RAMS vs. a Standalone Risk Assessment
If you're working under a Risk Assessment and Method Statement (RAMS), remember that both documents need to remain accurate together. If the method changes — say you switch from a scaffold to a mobile elevated work platform — the risk assessment changes too, because the hazard profile is different. Both parts of the RAMS should be updated and re-briefed to the team before work continues.
This is especially important on CDM 2015 projects, where the principal contractor must ensure that pre-construction information and site-specific risks are reflected in current documentation throughout the project lifecycle.
Record-Keeping: What You Need to Keep
If you employ five or more people, you must record the significant findings of your risk assessment in writing. Fewer than five, and there's no strict legal duty to write it down — but doing so is strongly advisable and often required by clients or insurers.
When you carry out a review:
- Record the review date and who carried it out
- Note what was checked and whether controls remain adequate
- Document any changes made as a result of the review
- Re-brief affected workers — a revised assessment that no one has read offers no real protection
The Bottom Line
There's no single answer to how often you should review a risk assessment, because the law focuses on validity rather than time. In practice, build in at least an annual check for ongoing work, review immediately after any incident or significant change, and always revisit your RAMS when the scope of work shifts. Treat your risk assessment as a live document, not a one-off exercise — because that's exactly how the HSE treats it.