What Is a Permit to Dig and When Do You Need One?

Pro Site Docs · Guide

A permit to dig is not a legal document with a fixed format. It is a control: a signed check that everything needed to break ground safely has actually been done, for a defined area and a defined time. Sites use it because a cable strike costs tens of thousands of pounds and, too often, a life.

Where the duty comes from

The Construction (Design and Management) Regulations 2015, regulation 25, requires all practicable steps to prevent danger from underground services before and during excavation work. The Health and Safety at Work etc. Act 1974 and the Electricity at Work Regulations 1989 sit behind it. HSE's guidance HSG47 Avoiding danger from underground services sets out how: plan, locate, dig. A permit to dig is the paperwork that proves each of those steps happened.

What a permit to dig checks

• Plans — utility drawings obtained for the exact location, in date, and on site (not in the office)
• Location — the area scanned by a trained operator with a cable avoidance tool and signal generator, in more than one direction, over the full footprint
• Marking — services marked on the ground, and the marks still visible when digging starts
• Trial holes — hand-dug to confirm depth and position of anything the scan found
• Method — hand digging within the safe distance of known services, insulated tools where electricity may be present, no mechanical excavation over a live service
• Isolation — where a service can be isolated, whether it has been, and proof of it
• People — the excavator operator, banksman and supervisor named, with their competence checked
• Area and duration — the exact area the permit covers and when it expires

Who issues it and who signs it

The permit is issued by an authorised person for the principal contractor or the contractor in control of the area — usually the site manager or a nominated supervisor — and accepted by the person supervising the dig. Both sign. The issuer confirms the checks; the acceptor confirms they understand the limits and will stop if anything unexpected is found.

The two ways permits go wrong

The first is the permit that covers 'the site' for 'the duration of works'. That is not a permit, it is a piece of paper. A permit covers a defined area for a defined shift or day; when the time runs out or the work moves, it is closed and a new one issued.

The second is the permit signed in the cabin at 7am without anyone walking the ground. If the scan was yesterday and the marks have washed off, the permit is not valid.

What to keep

Completed permits are records under CDM. Keep them with the site file, with the utility drawings and the CAT check records, for the life of the project. If a service is struck, they are the first thing an investigator asks for.

Get the documents ready-made

Our underground services templates cover the cat and genny procedure and permit to dig, and the Excavation & Trench Safety Pack covers the whole dig.

General guidance only. This article explains how the rules generally work in UK construction. It is not advice for your specific site, task or project, and it is not legal advice. Your own risk assessment, method statement and arrangements must be prepared and checked by a competent person for the actual work being done.