Why You Need a Written Permit to Work

A permit to work (PTW) is more than a tick-box exercise. It's a formal document that proves dangerous work has been properly assessed, authorised, and controlled before anyone picks up a tool. Without one, you're relying on verbal instructions and memory—a recipe for serious incidents.

HSE enforcement officers routinely check for permits during site inspections. If you can't produce a valid, completed permit for high-risk activities, you're looking at improvement notices, prohibition notices, or worse. In 2024/25, inadequate permit systems were cited in over 200 HSE enforcement actions across UK construction.

When Is a Permit to Work Legally Required?

There's no single regulation that says "you must have a permit." Instead, the duty comes from multiple pieces of legislation that require formal authorisation for specific high-risk work:

• Hot work — BS 9999 and insurer requirements mandate formal hot work permits
• Confined space entry — Confined Spaces Regulations 1997 require a safe system of work, best evidenced by a permit
• Electrical isolation — Electricity at Work Regulations 1989 require formal isolation procedures
• Work on pressurised systems — Pressure Systems Safety Regulations 2000
• Excavations near services — HSG47 guidance strongly recommends permits
• Roof work and fragile surfaces — Work at Height Regulations 2005, where additional controls are needed
• Breaking into live systems — Water, gas, or other service connections

Even where not strictly mandated, a permit system is considered best practice for any work where the consequences of failure are severe.

Step 1: Identify the Work and Hazards

Before writing anything, you need to understand exactly what work is being done and what could go wrong. This means:

• Visiting the work location and inspecting conditions
• Reviewing the RAMS for the task
• Identifying all hazards — not just the obvious ones, but interactions with other trades, existing services, and environmental factors
• Determining who else might be affected by the work

A permit written from behind a desk without visiting the work area is worthless. The whole point is that conditions have been physically verified.

Step 2: Define the Scope and Limitations

Every permit must clearly state:

• What work is authorised (specific activities only)
• Where the work will take place (exact location, not "somewhere on level 3")
• When it's valid (start time, end time, and any shift handover requirements)
• Who is authorised to carry out the work (named individuals or competent persons)
• What is NOT permitted — exclusions are just as important as inclusions

A permit that says "hot work in building" is useless. It should say "hot work — cutting steel beam B7 on level 2, grid line C3-C4, between 08:00 and 12:00 on 14 February 2026."

Step 3: List the Precautions and Controls

This is the heart of the permit. For each hazard, document the specific controls that must be in place before work begins:

Example: Hot Work Permit Controls

• All combustible materials removed within 10m radius or covered with fire-retardant sheeting
• Fire extinguisher (CO2 or dry powder) positioned within 2m of work area
• Fire watch maintained during work and for 60 minutes after completion
• Smoke detection in area temporarily isolated (with fire alarm panel notification)
• Welding screens erected to prevent spark travel
• Floors below checked and protected where sparks could fall through gaps

Example: Confined Space Entry Controls

• Atmospheric monitoring completed — O2, LEL, H2S, CO readings within safe limits
• Continuous gas monitoring in place during entry
• Emergency rescue plan in place with trained standby person at entry point
• Communication system tested between entrant and standby person
• Mechanical ventilation running for minimum 15 minutes before entry
• All connected pipework blanked or isolated

Step 4: Authorisation and Sign-Off

A permit requires signatures from specific people at specific stages:

• Permit issuer — A competent person (usually the site manager or safety advisor) who has inspected conditions and confirmed controls are in place
• Permit receiver — The person carrying out the work, confirming they understand the hazards, controls, and limitations
• Additional authorisation — For some work (e.g., breaking into live electrical systems), a second authoriser may be required

Both parties must sign before work begins. A permit signed after the work has started is a formality, not a safety document.

Step 5: Monitoring and Extensions

Once work is underway:

• The permit issuer should check that conditions haven't changed
• If the work takes longer than permitted, a new permit or formal extension must be issued — you can't just scribble a new time on the existing permit
• If conditions change (weather, adjacent work, unexpected discoveries), the permit must be suspended and reissued
• If the work scope changes, a new permit is needed

Step 6: Closure and Handback

When work is complete, the permit must be formally closed:

• The work area is inspected and confirmed safe
• All tools and equipment are removed
• Any temporary isolations are removed (or confirmed as permanent)
• Any fire watch period has been completed
• The permit receiver signs to confirm completion
• The permit issuer signs to accept handback

Closed permits must be retained on file. Many companies keep them for the duration of the project plus a minimum of 3 years.

Common Permit to Work Mistakes

After reviewing hundreds of construction permits, these are the most frequent issues:

• Generic descriptions — "General hot work" instead of specifying the exact task and location
• No time limit — Permits left open indefinitely defeat the purpose of periodic review
• Pre-signed permits — Signing before visiting the work area means conditions weren't actually checked
• No cross-referencing with RAMS — The permit should reference the relevant RAMS document
• Missing cancellation procedure — What happens if conditions change mid-shift?
• No permit register — Without a log of all live permits, you can't manage concurrent activities safely
• Photocopied signatures — Each permit must be individually signed

Digital vs Paper Permits

Paper permit systems work but have significant drawbacks — they get lost, damaged, and are hard to audit. Digital permit systems offer:

• Real-time visibility of all live permits across the site
• Automatic expiry alerts so permits don't overrun
• Photo evidence of conditions before and after work
• Audit trails that can't be tampered with
• Integration with site induction and access control systems

Whether you use paper or digital, the process matters more than the format. A well-managed paper system beats a poorly used digital one.

Create Your Permit to Work with DocGen

DocGen's AI document generator can create permit to work templates tailored to your specific activities. Describe the work, and it generates a fully structured permit with appropriate controls, sign-off sections, and handback procedures — ready to print or use digitally on site.