Free · Validity guide · Great Britain (HSE guidance)
What is a permit to work, and how long is one valid?
For the stated period only
A permit to work is a written authorisation for a specific high-risk job, such as hot work, entry into vessels or work needing isolation. It is valid only for the time written on it, is amended or cancelled if the work changes, and is closed out when finished.
Work out your permit to work expiry date
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Permits usually cover a task or a shift, so the calculator is of limited use. Use it to schedule the review of your permit-to-work procedure instead.
Enter a date to see when it expires, how many days are left, when to book the renewal, and to add reminders to your calendar.
Who needs a permit to work
Sites where contractors or staff carry out non-routine, high-risk work: maintenance on live plant, hot work, confined spaces, roof work, electrical isolations. HSE says a permit is not a substitute for a risk assessment but a way of putting it into practice on site.
What happens if it expires
- Work must stop when the permit’s time runs out unless it is formally extended or re-issued by the authorising person.
- If the scope changes, the permit is amended or cancelled by the person who issued it.
How to renew
Define the task and hazards
Describe the work, the location and the precautions from the risk assessment.
Issue with a clear time window
State valid-from and valid-to times and dates.
Hand over at shift change
Leave the work safe and pass clear instructions to the next shift.
Close out
Cancel the permit when the work is complete and everyone has left the area, and hand the plant back.
When to book
0
weeks
Permits are raised for the day of the work; contractor documents behind them (insurance, competence cards, RAMS) need checking well before.
A simple reminder plan: 1 days before the expiry date. The calculator above puts these in your calendar.
Evidence to keep
- Each permit with its unique number, times and signatures.
- A permit register where several permits run at once.
- The contractor documents checked before issue.
Common mistakes
- Open-ended permits with no end time.
- Treating the permit as the risk assessment.
- Not closing permits out, so nobody knows if plant is safe to restart.
For teams and managers
Running permits for contractors on your sites?
ExpiryEdge turns the permit procedure into a checklist with photo, signature and timestamp per step, and makes sure the contractor’s insurance and competence cards are current before the permit is issued.
See contractor documents for FM and propertyExpiryEdge · Tracked item
Hot work permit · Plant room, Level 2
ValidOwner
Site manager
Expires
1 month after issue
Reminders before expiry
1d
Due
Permit to work questions, answered
A formal written system that sets out the work to be done, when, and which parts of the plant are safe, signed by the people doing and authorising the work.
Only for the time written on it, usually a task or a shift. If work runs over or changes, the permit is extended, amended or re-issued by the authorising person.
HSE gives examples such as hot work like welding, vessel entry, cutting into pipework carrying hazardous substances, and work that needs electrical or mechanical isolation.
Sources
Every rule on this page comes from these official sources.
1.
Why are permit to work systems important?HSE · hse.gov.uk · checked 25 Oct 2026
2.
Permit to work guidance (SC 197)SafeContractor · safecontractor.com · checked 25 Oct 2026
3.
HSG250 Guidance on permit-to-work systemsHSE · hse.gov.uk · checked 25 Oct 2026
Guidance, not legal advice. This covers Great Britain (HSE guidance) and reflects the sources as checked on 25 Oct 2026. Check the official source or take professional advice for your situation.