A permit to dig is a formal written authorisation that must be issued, checked, and signed before any excavation work begins on a site where buried services or other sub-surface hazards are present. It does three things: it confirms that the hazards in the excavation zone have been identified, it records the controls that must be in place before and during digging, and it creates a named chain of accountability from the person who requests the dig to the person who signs it off.
No single UK regulation prescribes a document called a "permit to dig" by that name. Instead, a cluster of statutory instruments — taken together — creates duties that a permit-to-dig system satisfies in practice. Understanding which regulation drives which field on the form is the difference between a permit that protects workers and one that just ticks a box.
Permit to Dig vs Permit to Excavate: Is There a Difference?
In UK practice the two terms are used interchangeably and refer to the same control document. Some principal contractors prefer "permit to excavate" to distinguish the document from a local authority street-works permit (issued under the New Roads and Street Works Act 1991), which is an entirely separate legal instrument issued by a highway authority. Do not conflate a highway authority street-works permit with a site-level permit-to-dig system. This article covers the site-level safety permit only.
When Is a Permit to Dig Required?
A permit to dig should be raised whenever excavation work could intersect with:
- Buried services — gas mains, electricity cables, water and sewerage pipes, telecommunications ducts, district heating pipes
- Contaminated or unknown ground — brownfield sites, former industrial land, infilled areas
- Ground that could constitute a confined space — where the excavation depth and configuration could trap a worker and restrict escape or rescue
- Areas near high-voltage power lines or electrical infrastructure
- Ground where flammable or explosive atmospheres may be created — for example near gas distribution infrastructure
Even on greenfield sites where services are mapped and shallow, a permit provides the documented checkpoint that controls have been verified before digging starts. Most principal contractors require one for any powered excavation regardless of apparent risk.
The Regulatory Framework: Which UK Laws Make a Permit to Dig Necessary
No single regulation mandates the specific document. The legal case for a permit to dig is built from several statutory instruments acting together:
Construction (Design and Management) Regulations 2015 — The primary UK statutory instrument governing how construction projects are planned and managed safely, including groundworks (CDM 2015). CDM 2015 includes specific provisions on excavations (regulation 22) and on energy distribution installations (regulation 25), and Schedule 3 identifies work which puts workers at risk of burial under earthfalls as work involving particular risks. The Principal Contractor's duty to manage the construction phase safely — including groundworks — is the overarching management framework within which a permit to dig sits.
Electricity at Work Regulations 1989 — These impose duties relevant to work carried out near or around electrical conductors, including buried cables (EaWR 1989). The permit's buried-services field exists because of this duty.
Confined Spaces Regulations 1997 — A UK statutory instrument that imposes duties relevant to excavations deep enough to constitute a confined space (CSR 1997). Not all excavations are confined spaces. The confined-space assessment field on the permit becomes mandatory only where the excavation meets the definition.
Control of Substances Hazardous to Health Regulations 2002 (COSHH) — Relevant where excavation may disturb contaminated ground or generate hazardous dust (COSHH 2002), driving the ground-contamination assessment field.
Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) — Relevant where excavation work may encounter flammable gas or create an explosive atmosphere, for example near gas infrastructure (DSEAR 2002). DSEAR is not relevant to every permit-to-dig situation — only where a flammable or explosive atmosphere may be present.
Manual Handling Operations Regulations 1992 — Relevant to the physical tasks involved in excavation work, including spoil removal and equipment handling (MHOR 1992), and should be referenced in the risk assessment attached to the permit.
Work at Height Regulations 2005 — The WAH Regulations aim to prevent death and injury from falls (INDG401). Falls from height are one of the biggest causes of workplace fatalities and major injuries, and open excavations are a fall hazard for workers entering or working adjacent to them, making edge-protection controls a permit requirement.
The Unique Asset: Worked Example — Permit to Dig on a Live Commercial Site
Scenario: A groundworks subcontractor is asked to excavate a 600 mm wide trench for a new surface-water drainage run across a live commercial campus. The campus has been occupied since the 1970s. Utility plans show a telecoms duct and a 415 V armoured cable within the zone. Work will be carried out using a mini-excavator with hand-dig in the vicinity of mapped services.
Field-by-Field Annotation Table
| Permit Field | What Must Be Confirmed Before Signing | Which Regulation / Duty Makes This Necessary | Who Holds the Pen |
|---|---|---|---|
| Site location and trench reference | Exact grid reference or plan extract; trench start/end coordinates | CDM 2015 — construction phase plan must describe the work | Principal Contractor's site manager |
| Date and time of issue / expiry | Single shift or working day; expiry time stated explicitly | CDM 2015 management duty; permit is time-limited by convention | Issuing authority (PC site manager) |
| Description of excavation works | Depth (600 mm), width, method (mechanical then hand-dig), length | CDM 2015 reg 22 — excavation controls | Issuing authority |
| Buried services survey | CAT scan result, Dial Before You Dig / LSBUD search, architect's as-built drawings reviewed and dated | Electricity at Work Regulations 1989 — duties near electrical conductors | Competent person who conducted the survey |
| Services identified in zone | 415 V armoured cable (mapped, depth unconfirmed); telecoms duct (mapped at 400 mm depth); note: depth confirmation required by hand-dig | EaWR 1989; CDM 2015 reg 25 | Competent person |
| Exclusion zone / safe dig distance | Minimum safe distance from mapped cables confirmed; hand-dig only within [exclusion zone width per site rules] of any mapped service | EaWR 1989 | PC site manager and operatives' supervisor |
| Confined space assessment | Trench depth 600 mm — does not meet confined space definition at this dimension; reassess if depth increases beyond planned level | Confined Spaces Regulations 1997 — applies only if excavation meets the definition | Competent person / supervisor |
| Ground contamination assessment | Site history: commercial campus since 1970s; no known contamination; visual inspection of arisings required during dig | COSHH 2002 | Site manager / competent person |
| Explosive atmosphere check | No gas infrastructure in zone per utility plans; DSEAR 2002 not triggered for this permit — confirm at start of each shift | DSEAR 2002 — relevant only where flammable/explosive atmosphere possible | Operative and supervisor |
| Edge protection / fall prevention | Barriers or spoil bunding required on excavation edges; adjacent pedestrian route to be cordoned off | Work at Height Regulations 2005 — open excavations are a fall-from-height hazard | Site manager |
| Manual handling controls | Spoil removal: mechanical plant to be used; hand-digging near cables only with appropriate tools; task briefed | Manual Handling Operations Regulations 1992 | Supervisor |
| PPE required | Hard hat, high-vis, steel-toecap boots, cut-resistant gloves for hand-dig near cables, safety glasses | Site rules + task risk assessment | Operative confirms receipt |
| Emergency arrangements | First aider on site; emergency contact numbers on permit; cable strike drill briefed | CDM 2015 emergency-procedure duties and project/site emergency arrangements | PC site manager |
| Operative names and signatures | All operatives named; each signs to confirm they have read the permit and received the briefing | CDM 2015 — contractor duty to provide information and instruction | Each operative |
| Issuing authority signature | PC site manager (or delegated competent person) signs to confirm all pre-conditions are met | CDM 2015 — Principal Contractor's management duty | PC site manager |
| Closeout signature | Work completed, trench reinstated or made safe, no services struck, permit returned and signed off | CDM 2015 — audit trail requirement | PC site manager |
Permit-Breaking Events: When a Permit Is Automatically Void and Must Be Reissued
This list is absent from virtually every competitor page. The following events automatically void an active permit to dig and require a new permit to be raised from scratch — no work should continue on the original permit after any of these occur:
- A cable or pipe strike — work stops immediately; emergency procedures activate; incident recorded; a new survey must be completed before any new permit is issued
- Discovery of an unmapped service — stop work; notify PC site manager; update utility records; reissue permit with revised controls
- Discovery of contaminated material or unexpected ground conditions — stop work; COSHH assessment reviewed; reissue permit
- Change in operative team — any operative not named on the current permit must not work under it; reissue or formally amend the permit with the new operative's briefing confirmed
- Change in excavation scope — deeper trench, wider footprint, or change of method (e.g. moving from hand-dig to mechanical) triggers a new permit
- Significant weather event — heavy rain causing trench-side instability; waterlogged ground increasing collapse risk; reassess and reissue
- Introduction of additional plant or equipment in the excavation zone that was not present when the permit was issued
- End of shift / next working day — if the permit is issued for a single shift or day, work the following shift requires a fresh permit even if conditions appear unchanged
- Permit expiry time reached — a permit with a stated expiry time is void at that time regardless of whether work is complete
Who Issues, Signs, and Cancels a Permit to Dig: Roles Under CDM 2015
Under the Construction (Design and Management) Regulations 2015, duty-holder roles are:
- Client — has duties in relation to managing the project and ensuring suitable arrangements are in place for the construction phase
- Principal Designer — manages health and safety during the pre-construction phase and coordinates information that is relevant to planning and managing the construction phase safely
- Principal Contractor — manages the construction phase; under CDM 2015 this includes the duty to plan, manage, monitor and coordinate health and safety, which is the management framework within which the permit-to-dig system operates
- Contractors — must plan, manage and monitor their own work and that of workers under their control
In practice, the Principal Contractor's site manager (or a delegated competent person) issues and signs the permit. The operative or supervisor signs to confirm receipt of the briefing. The PC site manager (or delegate) closes and cancels the permit at the end of the authorised period or when a permit-breaking event occurs. On sites with multiple tiers of subcontracting, the issuing authority must be clearly identified in the site's permit procedure — ambiguity about who holds that authority is a common failure mode.
Permit to Dig Lifecycle: From Request to Archive
[1] REQUEST
Subcontractor/supervisor raises excavation request
↓
[2] PRE-WORK SURVEY
CAT scan + utility records search + site walk
→ CDM 2015: pre-construction information feeds this step
↓
[3] PERMIT ISSUED
PC site manager reviews survey, confirms controls, signs
Operatives briefed and sign permit
↓
[4] ACTIVE WORK
Excavation proceeds within permit conditions
Supervisor monitors continuously
↓
[5] SUSPENSION TRIGGER?
Any permit-breaking event (see list above)
→ STOP WORK → notify PC site manager → return to step 2
↓
[6] CLOSEOUT
Work complete or shift end
PC site manager signs closeout
↓
[7] ARCHIVE
Completed permit retained in project records
(supports post-project audit and incident investigation)
Common Failures That Expose Duty-Holders to Legal Liability
| Failure | Who Bears Exposure | Why It Matters |
|---|---|---|
| Excavation starts before permit is signed | Operative + contractor + PC | No documented confirmation that services survey was completed |
| Permit issued without a current CAT scan | Issuing authority (PC) | EaWR 1989 duties not satisfied; no evidence of precaution against live cables |
| Operatives not named or briefed on permit | Contractor | CDM 2015 duty to provide information to workers not met |
| Permit not cancelled and reissued after cable strike | PC + contractor | Continuation of work without reassessment; potential RIDDOR reportable incident without proper investigation |
| No confined-space assessment documented | PC + contractor | If excavation depth increases and no confined-space assessment was made, CSR 1997 duties may be breached |
| Permit retained by operative rather than returned to PC | PC (audit gap) | No close-out record; gap in project audit trail |
| Work continues past permit expiry time | Operative + supervisor | Working without valid authorisation; any incident during that period has no permit documentation |
How ramsdocs Digitises the Permit-to-Dig Process
Managing permits on paper creates real audit risk: permits get lost, expiry times are missed, and close-out records end up in a site cabin rather than the project file. ramsdocs provides a single digital workspace where the permit template, the issue log, and the close-out record sit together.
- Permit template pre-populated with your site details and utility survey fields; review and adapt to your specific site, task and contractor before issue
- Issue log timestamps every permit raised, showing operative names, issue time, and stated expiry
- Suspension and reissue workflow flags permit-breaking events and creates an audit trail of the stop-work decision
- Close-out record linked to the original permit; the full chain from request to archive is visible in one place, ready for PC review or HSE inspection
Important: All ramsdocs permit documents must be reviewed and adapted to the specific site, task and contractor by a competent person before issue. ramsdocs does not guarantee regulatory compliance or principal contractor acceptance.
Frequently Asked Questions
What is a permit to dig and what does it do? It is a formal written authorisation that confirms hazards have been identified, controls are in place, and named operatives have been briefed before excavation begins. It creates a documented chain of accountability.
When is a permit to dig legally required in the UK? No single regulation mandates the document by name. The combination of CDM 2015, the Electricity at Work Regulations 1989, the Confined Spaces Regulations 1997, COSHH 2002, and DSEAR 2002 creates duties that a permit-to-dig system satisfies. Most principal contractors require one for any powered excavation on a managed site.
What must a permit to dig contain? As a minimum: site location, trench description, date/time of issue and expiry, buried services survey result, identified services in zone, exclusion distances, confined-space assessment, ground contamination status, explosive atmosphere check, edge protection controls, PPE requirements, emergency arrangements, operative names and signatures, and an issuing authority signature.
Who issues, signs, and cancels a permit to dig? The Principal Contractor's site manager (or delegated competent person) issues and cancels it. Each operative named on the permit signs to confirm they have been briefed.
How does a permit to dig relate to buried services? The Electricity at Work Regulations 1989 impose duties relevant to work near electrical conductors including buried cables. The buried-services survey field on the permit is the documented evidence that those duties have been addressed.
How long is a permit to dig valid? Permits are typically valid for a single shift or working day. Any permit-breaking event (cable strike, change in scope, change in operative team, expiry time reached) voids it immediately and requires a new permit from scratch.
What is the difference between a permit to dig and a permit to excavate? In UK site practice, none — the terms are interchangeable. Both refer to the same site-level safety document. They are distinct from a highway authority street-works permit issued under the New Roads and Street Works Act 1991.
What regulations underpin the permit-to-dig requirement? CDM 2015, Electricity at Work Regulations 1989, Confined Spaces Regulations 1997, COSHH 2002, DSEAR 2002 (where applicable), Manual Handling Operations Regulations 1992, and Work at Height Regulations 2005.
What happens if excavation starts without a valid permit to dig? The operative, their employer, and the Principal Contractor all carry potential legal exposure. There is no documented evidence that the pre-work survey was completed or that operatives were briefed. If a cable strike or collapse occurs in those circumstances, the absence of a permit is a significant aggravating factor in any HSE investigation or civil claim.
Does the pre-construction information provided under CDM 2015 feed directly into the permit-to-dig process, and what role does a Ground Investigation Report play? Yes — CDM 2015 places duties on the client, assisted by the principal designer where one is appointed, to gather and pass on pre-construction information before work begins, including known locations of underground services; this package is a mandatory input to the permit, not an optional reference. Where a Ground Investigation Report (GIR) has been commissioned, it should be reviewed alongside utility-provider plans and CAT survey results when completing the buried-services field, because a GIR may identify obstructions, voids, or service crossings that do not appear on utility records. Remember that as "Avoiding danger from underground services" (HSE) notes, plans alone are not sufficient and on-site detection must still be carried out, since recorded depths and positions can be inaccurate. Treat GIR data as a supplementary source, not a substitute for physical detection.
Where excavation requires shoring, trench boxes, or sheet piling, how does a Temporary Works procedure sit alongside the permit to dig? A permit to dig controls the hazards of breaking and working in the ground; a Temporary Works (TW) procedure controls the structural adequacy of any support system installed to prevent collapse — these are two distinct processes that run in parallel and must both be in place before excavation proceeds. The TW process typically requires a designer to produce or approve the support scheme and a Temporary Works Coordinator (TWC) to issue a separate permit or approval notice before the support is loaded or relied upon, whereas the permit to dig records that services have been located and safe-dig controls are active. Neither document substitutes for the other: a signed permit to dig does not authorise the removal of a trench box, and a TW approval does not confirm that buried-service controls are in place. Where both processes apply, confirm on the permit that TW approval is a prerequisite condition before excavation reaches the depth at which support becomes necessary.
This page is provided for general information only. All permit-to-dig documents must be reviewed and adapted to the specific site, task, and contractor by a competent person before use. Nothing on this page constitutes legal advice or guarantees regulatory compliance.
Sources Used
This guide is checked against official source material. Verify current legal duties against the live legislation and HSE guidance before relying on the content for a live project.
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