A permit to work is one of the most important safety control documents used in UK construction. For certain high-risk activities — hot work, work on live electrical systems, excavation near buried services, confined space entry — a permit to work is not optional. It is the formal mechanism through which high-risk work is controlled, authorised, and monitored before anyone starts.
This guide explains exactly what a permit to work is, when UK law requires one, the different types used in construction, and what each permit must include to be legally compliant.
What is a permit to work?
A permit to work is a formal document that authorises specific high-risk work to take place under defined conditions, for a defined period, with specific controls in place. It is part of a safe system of work — a structured approach to managing activities where the consequences of something going wrong are severe.
The HSE defines a permit to work as "a formal written system used to control certain types of work that are potentially hazardous." The key word is formal — a verbal instruction to "be careful with the gas" is not a permit to work. The document must be written, signed by an authorised person, and specify the exact scope of work, the controls in place, and the conditions under which the permit is valid.
A permit to work does three things:
It authorises — confirms that a competent person has assessed the hazards, that the necessary controls are in place, and that the work is approved to proceed.
It communicates — ensures everyone involved in the work knows exactly what is permitted, what precautions are required, and what the limitations are.
It controls — creates a documented record of when the work started, who carried it out, and when it was completed and the area made safe.
Is a permit to work a legal requirement?
A permit to work system is not universally mandated by a single piece of UK legislation. However, for specific types of high-risk work, the requirement to have a formal system of control — which in practice means a permit to work — is established by several regulations.
The Health and Safety at Work etc. Act 1974 requires employers to provide safe systems of work. For high-risk activities, a permit to work is the accepted mechanism for implementing a safe system of work — and the HSE expects to see one in place.
The Management of Health and Safety at Work Regulations 1999 require employers to implement preventive and protective measures identified through risk assessment. For activities like confined space entry, hot work near flammable materials, or work on live electrical systems, a permit to work is the standard control measure.
Specific regulations mandate formal permits for particular activities:
The Confined Spaces Regulations 1997 require a safe system of work for entry into any confined space. In practice this means a permit to work covering pre-entry atmospheric testing, rescue arrangements, and communication procedures — all of which must be documented.
The Electricity at Work Regulations 1989 require that work on live electrical systems is only carried out where it is unreasonable for the conductor to be made dead. Live electrical work must be formally authorised — which means a written electrical permit to work in virtually every situation.
Under CDM 2015, principal contractors must ensure that high-risk construction activities are properly planned and managed. Permit to work systems are a standard expectation for the high-risk activities listed in the CDM notifiable works threshold.
What types of permit to work are used in UK construction?
Different activities require different permits. The most commonly used permit types on UK construction sites are:
Hot work permit
A hot work permit is required whenever work involving open flame, sparks, or heat generation takes place in an area where flammable or combustible materials are present — or where their presence cannot be ruled out. Hot work includes welding, cutting, grinding, brazing, soldering, and the use of blow torches.
The consequences of hot work carried out without proper controls — fire, explosion, or smouldering that causes a fire hours after the work ends — are severe. Hot work fires are among the most common causes of serious fire incidents on UK construction sites, and many occur after the operatives have left the area.
A compliant hot work permit covers: the specific location and scope of work, the flammable materials present or nearby, the clearance distance maintained between the work and combustibles, the fire extinguisher provision at the point of work, the fire watch arrangements during work and for a period after the work ends (typically 60 minutes minimum), and the sign-off by both the authorising person and the operative carrying out the work.
→ Download the Hot Work Permit — £3.99
Permit to dig
A permit to dig — sometimes called an excavation permit — is required before any excavation or ground-breaking work in an area where buried services may be present. Striking a buried gas main, water main, or high-voltage electricity cable during excavation is one of the most serious hazards on any construction site.
Before excavation starts, the permit to dig process requires: verification that service drawings have been obtained, confirmation that a cable and pipe avoidance tool (CAT and Genny) has been used to locate buried services, identification of the depth and location of known services, specification of hand-digging requirements within the exclusion distance of known services, and authorisation from a competent person.
On most UK construction sites, no mechanical excavation is permitted until a permit to dig has been issued. This is a standard principal contractor requirement under CDM 2015.
→ Download the Permit to Dig — £3.99
Electrical permit to work
An electrical permit to work is required for any planned work on or near live electrical equipment where isolation cannot be achieved, or where work on a de-energised system requires formal control to prevent unintended re-energisation.
The Electricity at Work Regulations 1989 are clear that work on live conductors is only permitted where it is unreasonable in all the circumstances for the conductor to be made dead, or it is necessary for it to be live for the work to be done. In virtually every case, live electrical work requires a formal permit.
A compliant electrical permit to work covers: the specific circuit or equipment to be worked on, the isolation method and lock-off arrangements, verification that the system has been made dead (test, test, test procedure), the scope and limits of the work permitted, the names of the authorising engineer and the operative, and the clearance procedure when work is complete.
→ Download the Electrical Permit to Work — £3.99
Isolation of supply permit
Closely related to the electrical permit to work, an isolation of supply permit specifically documents the isolation of a defined electrical supply — confirming which circuits have been made dead, how the isolation has been secured (lock-off, warning notices), and who has authority to reinstate the supply when work is complete.
This document is particularly important on projects where multiple trades are working simultaneously and where there is a risk of another operative reinstating a supply without knowing that work is ongoing elsewhere in the system.
→ Download the Isolation of Supply Permit — £3.99
General permit to work
A general permit to work is used for high-risk activities that do not fall neatly into a specific category — work in plant rooms, maintenance activities in operational buildings, work near moving machinery, or any activity where a formal authorisation process adds a meaningful layer of control.
The general permit to work follows the same structure as more specific permits — scope of work, hazards identified, controls required, authorisation, and clearance — but can be adapted to the specific activity rather than following a fixed format.
→ Download the General Permit to Work — £3.99
Limitation of access permit
A limitation of access permit is used to control access to a specific area of a site — for example, a zone where overhead work is taking place and the area below must be restricted, or a section of a building where structural work creates a collapse risk.
The permit defines the boundaries of the restricted area, the reason for the restriction, the controls in place (barriers, signage, exclusion zone enforcement), who has authority to enter the area, and the conditions under which the restriction will be lifted.
→ Download the Limitation of Access Permit — £3.99
Ladder permit to work
A ladder permit to work is used on sites where the principal contractor requires formal authorisation before any work is carried out from a ladder or stepladder. It documents the pre-use inspection of the ladder, confirmation that ladder work is the most appropriate access method for the task (following the working at height hierarchy), the specific task to be carried out, and the duration of the work.
Not all principal contractors require a ladder permit — some manage ladder use through their working at height risk assessment and toolbox talk programme. But where a principal contractor's site rules specify a ladder permit, it must be in place before the ladder is used.
→ Download the Ladder Permit to Work — £3.99
What must a permit to work include?
Regardless of the type of permit, every permit to work should include the following elements:
Permit number and date — a unique reference number for tracking and record keeping, and the date the permit is issued.
Location — specific description of where the work will take place. Not just "on site" — the exact area, level, room, or zone.
Description of work — precise description of the task to be carried out under the permit. The permit only authorises the specific work described — any change in scope requires a new permit.
Hazards identified — the specific hazards associated with the work in that location. This should be drawn from the risk assessment for the activity.
Precautions required — the specific controls that must be in place before work starts. For a hot work permit this includes clearing combustibles and posting a fire watch. For a permit to dig this includes CAT survey and hand-digging zones. The precautions are not suggestions — they are conditions of the permit.
Duration — the time period for which the permit is valid. A permit to work is not an open-ended authorisation. Most permits are issued for a single shift or a defined time period. If the work continues beyond that period, the permit must be renewed.
Authorising signature — the permit must be signed by a competent person who has the authority to issue it and who has verified that the precautions are in place before signing.
Operative signature — the person carrying out the work signs to confirm they have read and understood the permit conditions and will comply with them.
Clearance/completion — when the work is finished, the area is made safe, and the permit is formally closed out. The authorising person signs off to confirm the work is complete and normal conditions are restored.
Common mistakes with permit to work systems
Issuing the permit before the precautions are in place. The authorising signature confirms that the precautions specified in the permit are in place at the time of signing. Signing a permit in advance, before the controls have been implemented, defeats the purpose entirely.
Permits that are too vague. A permit describing the work as "electrical maintenance" or "welding" is not specific enough. The permit must describe exactly what work is authorised, in exactly which location, for exactly which time period.
No clearance procedure. A permit that is never formally closed out creates uncertainty about whether the work has been completed and whether normal conditions have been restored. Every permit must have a signed clearance section.
One permit for multiple activities. Each high-risk activity requires its own permit. Hot work and confined space entry on the same day in the same area require separate permits — they have different hazards and different controls.
No review when conditions change. If the scope of work changes, the time period expires, or site conditions change significantly, the permit must be reviewed and reissued. Carrying on under an expired or no-longer-applicable permit is a serious failing.
Browse all SafetyPod permit templates
SafetyPod offers a complete range of professionally drafted, HSE-compliant permit to work templates for UK construction — covering hot work, permit to dig, electrical, isolation of supply, general permit, limitation of access, and ladder permits.
Each template is fully editable in Word, ready to adapt to your specific job, and designed to meet the expectations of UK principal contractors and HSE inspectors.
→ Browse all RAMS and permit templates
Frequently asked questions
Who can authorise a permit to work?
The authorising person must be a competent person — someone with the knowledge, experience, and authority to verify that the precautions specified in the permit are in place and that the work is safe to proceed. For an electrical permit to work this is typically a qualified electrician or electrical engineer. For a hot work permit it may be the site manager or H&S advisor. The key requirement is competence in relation to the specific hazard.
How long is a permit to work valid for?
Most permits are issued for a single shift or a defined time period — typically no more than one working day. If the work continues beyond the validity period, the permit must be renewed by the authorising person after re-checking that the precautions are still in place.
Can one person both issue and work under a permit?
Generally no — the purpose of a permit to work is to introduce a second layer of authorisation and oversight. The person authorising the permit should be independent of the person carrying out the work. On very small sites with minimal staff, this separation can be difficult to maintain, but the principle should be followed wherever possible.
What records do I need to keep?
Completed permits to work should be retained as part of your site health and safety records. The HSE recommends keeping records for at least three years. Some principal contractors require permits to be held on site throughout the project and submitted as part of the project H&S file at handover.
Does a risk assessment replace a permit to work?
No. A risk assessment identifies the hazards and specifies the controls. A permit to work is the mechanism that confirms the controls are in place before work starts on a specific occasion. Both are required — the risk assessment informs the permit, but it does not replace it.
> Related: Many permit to work activities involve hazardous substances. Ensure a COSHH assessment is in place before issuing permits for work involving chemicals, solvents, or dusts.
Summary
A permit to work is the formal mechanism through which high-risk construction activities are authorised and controlled in the UK. For hot work, excavation near buried services, live electrical work, confined space entry, and other high-hazard activities, a permit to work is the standard expectation of principal contractors and HSE inspectors — and in many cases a legal requirement. A properly completed permit confirms that hazards have been identified, controls are in place, and an authorised person has approved the work to proceed.
SafetyPod has professionally drafted, HSE-compliant permit templates for every common permit type used in UK construction — ready to download and use in under 60 seconds.
→ Browse all permit to work templates
Written by the SafetyPod team — NEBOSH-qualified H&S professionals with hands-on experience across UK construction, civil engineering, and facilities management. All content is written to current HSE guidance and CDM 2015 compliance.
Last reviewed: May 2026