Appropriate filtering

Establishing appropriate levels of filtering

Guide for education settings and filtering providers about establishing ‘appropriate levels of filtering’

Accredited Filtering System

The UK Safer Internet Centre is pleased to announce that for the new year, we are releasing a new accreditation process for filtering providers. Given the critical role that filtering and monitoring services play in maintaining a safe and secure online environment in educational institutions, a comprehensive accreditation process is essential. The aim is to offer a credible, robust, and transparent benchmark against which to assess and validate the platforms schools may choose to implement. This accreditation seeks to validate the performance of providers systems to the UK Safer Internet Centre’s definitions. This information should help schools to audit their current provision, make informed decisions, and review market solutions. 

Schools in England (and Wales) are required to ensure children are safe from terrorist and extremist material when accessing the internet in school, including by establishing appropriate levels of filtering. Furthermore, the Department for Education’s statutory guidance ‘Keeping Children Safe in Education’ obliges schools and colleges in England to “ensure appropriate filters and appropriate monitoring systems are in place and regularly review their effectiveness” and they “should be doing all that they reasonably can to limit children’s exposure to the above risks from the school’s or college’s IT system” however, schools will need to “be careful that “over blocking” does not lead to unreasonable restrictions as to what children can be taught with regards to online teaching and safeguarding.” Ofsted concluded as far back as 2010 that “Pupils in the schools that had ‘managed’ systems had better knowledge and understanding of how to stay safe than those in schools with ‘locked down’ systems. Pupils were more vulnerable overall when schools used locked down systems because they were not given enough opportunities to learn how to assess and manage risk for themselves.”

To further support schools and colleges in England to meet digital and technology standards, the Department for Education published Filtering and Monitoring Standards in March 2023. In addition to aspects of both filtering and monitoring systems, these standards detail the allocation of roles and responsibilities, and that schools and colleges should be checking their filtering and monitoring provision at least annually.

The Welsh Government has published a common set of agreed standards for internet access provides the tools for schools to make informed choices over filtered provision whether delivered by the local authority or another provider

Previously included within the Scottish Government national action plan on internet safety, schools in Scotland are expected to “have policies in place relating to the use of IT and to use filtering as a means of restricting access to harmful content.”

The aim of this document is to help education settings (including Early years, schools and FE) and filtering providers comprehend what should be considered as ‘appropriate filtering’.

It is important to recognise that no filtering systems can be 100% effective and need to be supported with good teaching and learning practice and effective supervision. As such, filtering systems should be recognised as one of the tools used to support and inform the broader safeguarding provision in settings.

Illegal online content

In considering filtering providers or systems, schools should ensure that access to illegal content is blocked and that filters for illegal content cannot be disabled. Specifically that the filtering providers:

  • Are IWF members and use IWF services to block access to illegal Child Sexual Abuse Material (CSAM)
  • Integrate the ‘the police assessed list of unlawful terrorist content, produced on behalf of the Home Office’

Inappropriate Online Content

Recognising that no filter can guarantee to be 100% effective, schools should be satisfied that their filtering system manages the following content (and web search)

  • Discrimination – Promotes the unjust or prejudicial treatment of people with protected characteristics of the Equality Act 2010
  • Drugs / Substance abuse – displays or promotes the illegal use of drugs or substances
  • Extremism – promotes terrorism and terrorist ideologies, violence or intolerance
  • Gambling – enables gambling
  • Malware / Hacking – promotes the compromising of systems including anonymous browsing and other filter bypass tools as well as sites hosting malicious content
  • Pornography – displays sexual acts or explicit images
  • Piracy and copyright theft – includes illegal provision of copyrighted material
  • Self Harm – promotes or displays deliberate self harm (including suicide and eating disorders)
  • Violence – displays or promotes the use of physical force intended to hurt or kill

This list should not be considered an exhaustive list and providers will be able to demonstrate how their system manages this content and many other aspects.

Regarding the retention of logfile (Internet history), as the data controller, schools should understand their filtering providers data retention policies including the duration to which all data is retained and have associated data sharing agreements. Logfiles (Internet history) should include the identification of individuals and/or devices.

Providers should be clear how their system does not over block access so it does not lead to unreasonable restrictions. Welsh Government highlight that “It is critical that filtering standards are fit for purpose for 21st century teaching and learning, allowing the access schools require whilst still safeguarding children and young people.”

Given the extent of personal data involved with some filtering systems, Schools and Colleges should consider undertaking a Data Protection Impact Assessment and ensure that this aligns with the organisational policies.

Filtering system features

Additionally, and in context of their safeguarding needs, schools should consider how their filtering system meets the following principles

  • Context appropriate differentiated filtering, based on age, vulnerability and risk of harm – also includes the ability to vary filtering strength appropriate for staff
  • Circumvention – the extent and ability to identify and manage technologies and techniques used to circumvent the system, for example VPN, proxy services and DNS over HTTPS
  • Control – has the ability and ease of use that allows schools to control the filter themselves to permit or deny access to specific content. Any changes to the filter system are logged enabling an audit trail that ensure transparency and that individuals are not able to make unilateral changes.
  • Contextual Content Filters – in addition to URL or IP based filtering, the extent to which (http and https) content is analysed as it is streamed to the user and blocked, this would include AI generated content.  For example, being able to contextually analyse text on a page and dynamically filter.
  • Filtering Policy – the filtering provider publishes a rationale that details their approach to filtering with classification and categorisation as well as over blocking
  • Group / Multi-site Management – the ability for deployment of central policy and central oversight or dashboard
  • Identification – the filtering system should have the ability to identify users
  • Mobile and App content – mobile and app content is often delivered in entirely different mechanisms from that delivered through a traditional web browser.  To what extent does the filter system block inappropriate content via mobile and app technologies (beyond typical web browser delivered content). Providers should be clear about the capacity of their filtering system to manage content on mobile and web apps
  • Multiple language support – the ability for the system to manage relevant languages
  • Network level – filtering should be applied at ‘network level’ i.e., not reliant on any software on user devices whilst at school (recognising that device configuration/software may be required for filtering beyond the school infrastructure)
  • Remote devices – with many children and staff working remotely, the ability for school owned devices to receive the same or equilavent filtering to that provided in school
  • Reporting mechanism – the ability to report inappropriate content for access or blocking
  • Reports – the system offers clear historical information on the websites users have accessed or attempted to access
  • Safe Search – the ability to enforce ‘safe search’ when using search engines

Schools and Colleges should ensure that there is sufficient capability and capacity in those responsible for, and those managing, the filtering system (including any external support provider). The UK Safer Internet Centre Helpline may be a source of support for schools looking for further advice in this regard.

Filtering systems are only ever a tool in helping to safeguard children when online and schools have an obligation to “consider how children may be taught about safeguarding, including online, through teaching and learning opportunities, as part of providing a broad and balanced curriculum”. To assist schools and colleges in shaping an effective curriculum, UK Safer Internet Centre has published ProjectEVOLVE.

Risk assessment

UK Safer Internet Centre recommends that those responsible for Schools and Colleges undertake (and document) an online safety risk assessment at least annually or whenever any substantive changes occur, assessing their online safety provision that would include filtering (and monitoring) provision. The risk assessment should consider the risks that both children and staff may encounter online, together with associated mitigating actions and activities.

A risk assessment module has been integrated in 360 degree safe.  Here schools can consider identify and record the risks posed by technology and the internet to their school, children, staff and parents.

Checks and documentation

Schools and Colleges should regularly check that their filtering and monitoring systems are effective and applied to all devices. Checks should be conducted when significant changes take place (for example, technology, policy or legislation), in response to incidents and at least annually. These checks should be recorded, including details about the location, device and user alongside the result and any associated action.

SWGfL enables users to test fundamental capabilities of their filtering system and to inform improvement

Filtering on mobile devices

Schools and colleges should satisfy themselves that filtering systems are correctly working across all their devices’, including mobile devices. If your school owns mobile devices such as iPads or other tablets as part of your teaching strategy, then consider the following practices to ensure filtering is in place (you may need the help of your ICT support to do this):

  • Audit the mobile device estate by detailing all the mobile devices they have.
  • Understand and detail the applications (apps) they use and how these are managed (installed and deleted). Specifically, ensure that apps can be centrally, and routinely, removed from mobile devices. This is best achieved through the use of a Mobile Device Management (MDM).
  • Identify who is responsible for mobile devices as well as filtering and monitoring solutions at the school, ensuring that the DSL is also aware (if different).
  • Test to provide confidence that the schools filtering and monitoring solution is working across all mobile devices, across installed apps (not just internet browsers) and in various physical locations. Does filtering continue when away from the school network? Schools can use to help in this regard.
  • Identify any vulnerable users of mobile devices, paying particular attention to ensure harmful content is not accessible on specific devices

This detail has been developed by the SWGfL, as a partner of the UK Safer Internet Centre, and in partnership and consultation with the 80 national ‘360 degree safe Online Safety Mark’[1] assessors and the NEN Safeguarding group (

Be in the know

You’ll get knowledge, skills and tools to make the internet safer
for young people at your care. Each sent once per month.

Share your feedback:

This field is for validation purposes and should be left unchanged.