There are 12 Guiding Principles for CCTV

  1. Use of a surveillance camera system must always be for a specified purpose which is in pursuit of a legitimate aim and necessary to meet an identified pressing need.
  2. The use of a surveillance camera system must take into account its effect on individuals and their privacy, with regular reviews to ensure its use remains justified.
  3. There must be as much transparency in the use of a surveillance camera system as possible, including a published contact point for access to information and complaints.
  4. There must be clear responsibility and accountability for all surveillance camera system activities including images and information collected, held and used.
  5. Clear rules, policies and procedures must be in place before a surveillance camera system is used, and these must be communicated to all who need to comply with them.
  6. No more images and information should be stored than that which is strictly required for the stated purpose of a surveillance camera system, and such images and information should be deleted once their purposes have been discharged.
  7. Access to retained images and information should be restricted and there must be clearly defined rules on who can gain access and for what purpose such access is granted; the disclosure of images and information should only take place when it is necessary for such a purpose or for law enforcement purposes.
  8. Surveillance camera system operators should consider any approved operational, technical and competency standards relevant to a system and its purpose and work to meet and maintain those standards.
  9. Surveillance camera system images and information should be subject to appropriate security measures to safeguard against unauthorised access and use.
  10. There should be effective review and audit mechanisms to ensure legal requirements, policies and standards are complied with in practice, and regular reports should be published.
  11. When the use of a surveillance camera system is in pursuit of a legitimate aim, and there is a pressing need for its use, it should then be used in the most effective way to support public safety and law enforcement with the aim of processing images and information of evidential value.
  12. Any information used to support a surveillance camera system which compares against a reference database for matching purposes should be accurate and kept up to date.

What is needed in a CCTV system?

One of the most common failings in a CCTV system is having image sizes that are too small
to enable identification and recognition. The pictures below demonstrate how large a person
should look on screen, depending on the purpose of the camera.
Identify - Sufficient picture quality and detail to identify an individual beyond reasonable doubt.
Recognise - Viewers can say with a high degree of certainty whether or not an individual shown is the same as someone they have seen before.
Observe - Some characteristic details of the individual, such as distinctive clothing can be seen.
Screen height is how much space vertically a 1.7m tall figure would occupy, as shown in the diagram above

As a minimum, your system should therefore meet the following standard

  • At least one camera must provide identifiable quality images of everyone entering the premises, i.e. clear image of the face plus characteristics of clothing, items carried etc. The best place to capture these images is usually at the main doorway. It is strongly recommended that a second camera with similar capabilities is placed near the till.
  • The video signal from these cameras should be recorded at a minimum of six frames per second. All other cameras should record at six frames per second for higher risk locations or a minimum of two frames per second at lower risk locations.
  • Make sure the recorded image quality is similar to that of the live view. The video should be recorded at its original size with a minimal amount of compression. 

In addition to these cameras you should then identify the most important areas of the premises from the table and generic site plan above and ensure that they are also covered with additional cameras to the required standard.
As well as choosing the best location for the cameras, it is also important to consider the angle of view and lighting conditions as the pictures below illustrate. Additional lighting may need to be installed to achieve good quality images.

Storage and Retention. What should you keep and for how long?

  • The system should be capable of saving and securing recorded images for review or export at a later date.
  • Information should be kept secure and retained for no longer than is necessary for the purpose of the system. A minimum of 14 days is recommended for small CCTV systems.
  • The system clock should be set correctly and kept accurate (taking account of GMT and BST). This will be very important if a police investigation is carried out.


Playback and Export. Can the pictures be quickly reviewed and can the police take them away as evidence easily?

  • There should be someone available at all times who is trained and able to replay recordings and produce copies for the police.
  • The user should know the retention period of recordings
  • The system should be able to quickly export video and stills onto a removable storage medium e.g. CD/DVD with the time and date integral to the relevant picture and without any drop in quality.
  • Exported images should include any software needed to view or replay the pictures.

Who should install a CCTV system?

It is likely that there is a „monitored‟ intruder alarm. That company or another company who specialises in CCTV should be CCTV accredited by a UKAS approved scheme to ensure that the installation and subsequent maintenance are of a professional standard. The company should perform testing of the system using an approved audit and commissioning test and „prove‟ that the system meets the specified requirement. We recommend the Home Office CAST test targets, which can be found on the Home Office website.

Do they have to comply with the Data Protection Act?

Yes. The Information Commissioners‟ Office has published specific guidance on CCTV, which contains a lot of useful information and step by step help specifically for small businesses. Visit their website at