Martyn's Law notification guidance: the practical points to know and prepare for now

The latest Martyn's Law guidance confirms the details of the practical notification requirement for responsible persons under the Terrorism (Protection of Premises) Act 2025, and for many organisations it will require more preparation than the word 'notification' suggests.

Businesses will need to identify who is responsible, understand who they must co-ordinate with, calculate maximum expected capacity and be ready to provide that information within tight statutory deadlines. For event operators in particular, the notification window could be as short as 14 days from publicity.

What has changed?

The government issued further guidance on 14 July 2026 on the requirement to notify the Security Industry Authority (SIA) when a person becomes, or ceases to be, responsible for qualifying premises or a qualifying event. The guidance explains:

• how notifications will be made
• when responsible persons must notify
• what information must be included.

How notification will work

Notifications must be made using an online portal unless the SIA directs otherwise. The guidance does not yet explain how that portal will work, but confirms that further information will be published before the notification requirement comes into force.

There is reference to the possibility of use of another notification method if there are issues with the portal or if a responsible person cannot notify through the portal 'due to accessibility needs'.

When responsible persons will need to notify

Importantly, the guidance provides that those responsible for qualifying premises must notify the SIA within three months of the commencement date. Given that the minimum two year implementation period expires in April 2027, it is highly likely that operators will be required to comply with the notification provisions as early as July 2027. Businesses that may be in scope should therefore be making preparations immediately.

Any person that is responsible at the commencement date should notify within the first three months. Any person that becomes responsible within the initial three-month period must notify the SIA by the end of the three months, or within 28 days of becoming responsible, whichever is later. After that initial period, any new responsible person must notify the SIA within 28 days.

For qualifying events, the trigger for notification is when the event is 'first publicised' – meaning 'when the date of the event is first made available to members of the public for the purposes of advertising the event'. If an event is first publicised on or before the commencement date, notification must be made within 14 days of commencement. If the event is first publicised after that date, the notification must be within 14 days of that first publicity. This gives event organisers very little time to act once a date goes public. Notification should therefore be built into event planning, approval and publicity processes now, rather than treated as an administrative step at the end.  

What information will need to be ready?

The guidance provides a complete list of information that must be provided to the SIA. These include administrative items such as the name and address of the responsible person, but also two specific points that are likely to need more preparation:

1. Co-ordination contacts

Responsible persons must provide the name and contact details of any other person who is subject to obligations to co-ordinate with them. This could be more complex for multi-tenanted buildings, shared venues, retail estates, education campuses, hospitality sites and large event arrangements, where responsibility may not sit neatly with one organisation or one individual.

‍2. Maximum expected capacity – and how it was calculated

Responsible persons must state the greatest number of individuals who can reasonably be expected to be present at the same time and explain how that figure was reached. Organisations may need to review existing capacity assumptions, event planning documents, tenancy arrangements and operational records to make sure the figure is robust.

What should organisations do now?

Operators of premises or proposed events that are likely to be in scope should make immediate preparations for notification to ensure that they are compliant within the required time of the commencement date. In practice this means:

• identifying which premises or events may need to be notified
• confirming who the responsible person is
• mapping any co-ordination obligations with landlords, tenants, operators or event partners
• checking how maximum expected capacity is calculated and recorded
• building notification deadlines into premises management and event planning processes.

The organisations that prepare early will be better placed to meet the first notification deadlines and avoid last-minute gaps in responsibility, data or evidence.

If you would like support working out what the notification requirement means for your premises, events or wider estate, or the extent of your obligations under Martyn's Law, please get in touch.

This publication is intended for general guidance and represents our understanding of the relevant law and practice as at July 2026.  For more information see our terms & conditions.