Improvement and prohibition notices – effective drafting and service

OC 130/14


This guidance gives practical advice on drafting and serving enforcement (improvement and prohibition) notices in accordance with the Health and safety at Work, etc Act 1974 (HSWA) and the evidence needed to support that. It supplements the Enforcement Guides (for England & Wales, and Scotland).


Enforcement notices are key tools for addressing shortcomings but can fail to achieve the desired result if they are not prepared and/or served effectively. This guidance highlights common pitfalls and how to avoid them.


Follow the guidance in Appendix 1 (in conjunction with the Enforcement Policy Statement and the Enforcement Guides) when collecting evidence for, drafting and serving enforcement notices.

Inspectors should contact Legal Advisors Office (LAO) for specific legal advice.


The most familiar and commonly used enforcement notices are improvement and prohibition notices served in accordance with sections 21 and 22 of HSWA.  

But not all notices are HSWA; other legislation (such as the Control of Major Accident Hazards Regulations 1999), includes enforcement notice provisions.


No special organisational requirements

Further References

HSE Enforcement Guides:


Legal Advisors Office
Legal and Enforcement Team
HID HQ, Business Assurance Team

Appendix 1:  Tips for effective enforcement notices 

Tip Comments

1.   When considering whether to serve a notice, think about where your authority to do so comes from and the conditions attached to that right.

  • HSWA Section 21 – INs
  • HSWA Section 22 – PNs
  • HSWA Section 23 – Provisions supplementary to S21 & S22

Double check which is the correct Enforcing Authority if any doubt.

Appeals against notices may look at whether an inspector properly exercised their discretion. The enforcement guide sets out the ''Conditions for a valid notice' including the basis of your considered opinion, whether you acted reasonably, and the notice being sufficiently clear so that the person 'fairly knows what he has done wrong and what he has to do to put it right'.

The Enforcement Management Model (EMM) provides a framework to decide whether a notice is a proportionate and effective response.

You should note your reasons for all enforcement decisions in a durable and retrievable form, ideally your notebook. Some inspectors use the EMM decision form to record these decisions. It may also be necessary to take photographs and/or statements to collect critical evidence to support the notice.    

2.   Be aware of the some of the grounds for appeal

The enforcement guide covers the arrangements for Employment Tribunals in both England & Wales, and Scotland.  As the inspector you will have to argue that the notice is valid and that you complied with the conditions for serving a notice.

The Tribunal will expect you to have made reasonable enquiries into the circumstances at the date you served the notice. It is not limited to what you knew at the time. For example, an appellant may argue that the basis of the notice is wrong because the inspector did not know all the facts which he/she could have reasonably enquired about.

Remember, HSE bears the burden of proof (on balance of probabilities) of showing it was properly served

Be clear on what the duty holder had failed to do. In Chilcott V Thermal Transfer Ltd the Court held that the notice could not be upheld because it was aimed at planning (ie failure to have a method statement when in fact there was one) rather than supervision (ie failure to ensure the method statement was followed).

3.   When choosing what notice to serve, consider what you want to achieve. For example, evidence of a specific failure (eg failure to guard a machine) may also be a symptom of other failings that you will want to address. Both an IN and PN can be served covering the same issue if it is necessary, justifies and proportionate to do so.

The following reflects guidance in the enforcement manual.  

Both a PN and IN can be served on the same issue providing there are sufficient grounds for serving both dependent on HSE enforcement policy and EMM considerations. A PN may deal with the immediate risk of serious personal injury supported by an IN to deal with underlying failures such as inadequacies in management arrangements.

4.   Use the current template for the notice.

Regular updates/changes are made to notice formats and the notes section because of changes to legislation. There is a risk that a notice could be invalid if older templates are used.

The most up to date templates can be found on "Forms Desktop", under "Folder 10 – Legal".  For Improvement Notices LP1 (rev 03.10), and for Prohibition Notices LP2 (rev 03.10) should be used.

5.   The notice should state the role that the duty holder is being required to discharge, although a 'dutyholder' is not required if the risk of serious personal injury is evidenced.

This depends on the contravention you are alleging. For example:

  • the employer (HSWA s2(1))
  • the operator ….. (COMAH r4)
  • the person conveying gas ….. (GSMR r3)
  • the mine manager …..

The latest notice templates have free text boxes to allow the correct designation to be entered.

6.   Be specific and clear:

  • identify the specific location, plant and activity in the notice, and
  • be clear what compliance looks like.

The notice should make clear the location of where you believe there is a contravention. On a large and complex site, the location of plant (including serial numbers if possible) may be very important.

It is important to consider the question "what does compliance look like?"  A notice should be served with three important fundamental questions in mind:

  • will the recipient fairly understand what they have done wrong and what is required to put it right?  (Ormston V Horsham Rural District Council
  • will a tribunal be able to feel comfortable the notice has correctly addressed the relevant underlying requirement(s) and understand what compliance would look like? (Chilcott and BT Fleet v McKenna)
  • if there is non compliance would a jury understand what was required and what the defendant hasn't done?1

7.   State the correct contravention of the statutory provision. This requires careful consideration of the legal requirement and what you are of the opinion the duty holder has done wrong.

Examples include:

  • HSWA Section 2 – General duties
  • Section 2(1) sets out the duty
  • Sections 2(2)(a) – 2(2)(e) set out what that duty extends to include in particular.

If your reasonable opinion is that non-employees are not at risk then don't add section 3 as a catch all.  Only cite contraventions you genuinely believe there is evidence for.

PUWER Regulation 11:

  • A specific contravention eg r11(1)(a) should be stated, not a general contravention of r11.

COSHH Regulation 7:

  • The general duty is under regulation 7(1). This is extended by other requirements eg r7(10), Schedule 3 in relation to work with biological agents.
  • If failings relate to control measures, then r7(1) should be used. If not, r7(10) should be used.

Regulations may be written such that they flow from one to the other eg to assess risks and then implement arrangements. In these cases, based on the evidence, you need to be careful what you allege the duty holder has contravened.

8.   The subject matter of the notice should only cover one requirement.

For example, a single notice should not require both providing a certain machine with effective guarding and implementing a system to ensure guards are used properly. These should be dealt with by issuing two notices. 

9.   Minimise the number of legal provisions you put on the notice in respect of the single requirement you are addressing in the notice. If adding several relevant statutory provisions, consider if they add anything or are just being used as a 'catch all'. Be proportionate and avoid the latter.  

There may be a temptation to add several contraventions addressing a single requirement eg stating a breach of a specific regulation protecting the safety of employees and HSWA S2(1).

This may be legally acceptable but the notice should be clear what is wrong and what should be done to put things right and you should have evidence to support your decision.

As different legislation often uses different words and requires different evidence, there is greater scope for appeal. Best advice is to be proportionate and keep things as simple as possible.

10.  HSWA section 21 (INs) and 22 (PNs) requires you to state your opinion - giving particulars of the reasons for that opinion.

The wording you use should be sufficiently clear that the duty holder knows why you are of that opinion and what he has done wrong.

When stating the reasons for your opinion, use plain language and make sure it meets the requirements above. 

It is not sufficient simply to quote the legal provision in the reasons for your opinion. You have already done that by specifying the provision on the notice.

A test of whether the words are clear enough is to ask would the person 'fairly know what he has done wrong'. It is common practice to frame words around those used in the relevant provisions, for example:

  • 'so far as is reasonably practicable' (HSWA)
  • 'all measures necessary' (COMAH)
  • 'appropriate measures' (MSER)
  • 'effect to such arrangements' (MHSWR)
  • 'measures which are effective' (PUWER)

But ensure there is enough supporting information to explain why you have come to that opinion by including such phrases as:

  • 'in that you ….'
  • 'because ….' .  

11.  Use schedules with improvement notices.

Although not mandatory you should always include a schedule unless there are very good reasons for not doing so.

Further guidance may be included or referenced in a letter, but it should be clear that it does not form part of the notice.

HSWA S23(2)(a) gives the option to include directions as to the measures to be taken to remedy the contravention ie to include a schedule.

Remember the overriding requirement that the person needs to know what to do to put things right.

An accompanying letter may refer to or contain guidance but is not and cannot become part of the notice and you cannot refer to any such guidance in seeking to enforce the notice.

Therefore use schedules to tell dutyholders what they have to do to remedy the contravention. Make sure they are clear and concise and set the benchmark for compliance.

The notice and schedule serial numbers should be the same.

12.  Use the following phrase in the notice to give the recipient the option of choosing an alternative way of complying with it:

'Any other equally effective measures to remedy the said contravention'

The requirements in the schedule should not go beyond legal compliance, but to meet HSWA s23(2)(b) you should allow for alternative methods of achieving compliance.

Many variations on this wording have been found.  This is the wording agreed with LAO and using it ensures consistency.

13.  Schedules to improvement notices must not include ongoing requirements.

An improvement notice cannot be used to require a duty holder to do something which has no attainable end within the compliance period. This is described as an ongoing requirement.

For example, to require a person to maintain a guard in good condition would be ongoing. However, a notice could require a suitable system for maintaining guards to be in place by a given date.

14.  Attention to detail

A notice is a legal document and it is important you focus on the detail.

For example:

  • Ensure you use 'are contravening', 'have contravened' correctly;
  • If there is no schedule then delete 'and I direct that the measures…'.

15.  Ensure you state if the notice is relevant under the Environmental and Safety Information Act 1988 (ESIA)

In OSD ESIA does not apply because all persons on an installation/rig are deemed to be at work all of the time.

ESIA applies to HSE and to INs, PNs and COMAH PNs. ESIA s2(3) says:

The notices relevant for the purposes of this Act are those served under any of the provisions specified [……….] other than notices which impose requirements or prohibitions solely for the protection of persons at work.

Therefore notices which are relevant for ESIA are those affording protection to people not at work eg the public. Examples include risk from a cross country pipeline and off-site risks.

Inspectors should be aware of circumstances whereby the immediate risks may be to employees but there may also be potential for others not at work to be at risk. 

16.  Serve notices on the correct legal entity. 

This could be a plc, limited company, partnership or individual.

Where a notice is served on a partnership each partner should, in principle, be served with a notice individually, particularly if the division of responsibilities is unknown.

However, discretion may be exercised. Factors such as the nature of the offence and the division of responsibilities within the partnership may provide good reasons for excluding one or more partner.

Legalade newsletter 22 covered partnership issues. 

17.  Ensure the notice is served properly.

Section 46 HSWA details ways by which a notice may be served:

  • Section 46(2) allows for service by delivery or leaving at the recipient's proper address;
  • Section 46(3) for service on the company secretary or clerk of the body corporate or service on a partnership, by handing to a partner or person controlling or managing the partnership;
  • Section 46(4) provides that the address for service on the type of person in b) shall be the registered or principal office of the company or the principal office of the partnership;
  • Section 46(4) allows that the proper address of any person shall be his/her last known address. This does not apply to companies or partnerships (section 7 Interpretation Act 1978)

Section 46(6) allows service on the owner or occupier of premises.

18.  When issuing a PN, ask the recipient to sign it with the date and time they received it.

You cannot compel someone to sign on receipt of a PN. However, this practice is recommended and can be used to demonstrate it has been served properly.

19.  Use COMAH Prohibition Notices if there is evidence of a serious deficiency in the overall measures to prevent major accidents and to limit consequences.

See CA guidance Prohibition under COMAH.

COMAH prohibition requires evidence of a serious deficiency in the overall measures and be related to a major accident as defined. A deficiency in a single measure may not amount to a serious deficiency.

But if there is a serious deficiency, there is a duty on the CA to prohibit the operation.

If there is not a serious deficiency as defined by COMAH, a HSWA PN can be served and identified breaches of COMAH can be referred to. 

20.  A scanned pdf copy of the signed and dated notice must be attached to COIN.

Admin staff are responsible for inputting these details to COIN


1. LAO advice December 2012. Back

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Updated 2022-08-16