Custom Security Services is one of the South's leading independent providers of fire, security and safety systems. The company offers a comprehensive design, installation and maintenance service for all types of security related projects. With over 25 years experience the company has successfully delivered thousands of quality installations to all types of customers, including domestic, commercial, and public sector.

Cynon Valley Crime Reduction Services Limited is a non-for-profit social enterprise which is now in its 10th year of trading. It was set up to support the Charity side (Cynon Valley Crime Prevention Association) with sustainable funding, by providing security services across the country, these include fitting of security products like intruder alarm systems, CCTV, access control systems, UPVC locking systems, and key suiting/cutting services.

D-Fence Electronic Fencing and Security Systems Ltd. is an Israeli "Security-by-Technology" company that designs, develops and manufactures the most advanced Perimeter Intrusion Detection Systems (PIDS), based on an exclusive Strain Gauge Sensor technology. This proprietary technology allows us to offer highly aesthetic PIDS based on the “Open-Design” concept, and most importantly, that work with Zero False Alarms.

D&D Security Derby offers fully licensed SIA-approved security guards that are ready to be deployed within hours upon acceptence. It provides approved contractor security services for major companies across the UK. Specialists in static guarding, it offers a cost-effective security service for the protection of UK businesses.

DA Security Systems are a family run CCTV, Fire and Alarm Business. It has been operatiing from Lee-on-the-Solent in Hampshire, UK since 1984. It has over 40yrs experience with the installation and maintenance of CCTV, Fire Alarm, Intruder Alarm, Door Entry and Nurse Call systems.

DAS Technology can design, install and maintain security systems for a wide range of uses from homes, shops and offices to shopping centres, schools and car parks. They provide bespoke security solution that meets your needs, and all completely hassle free. Their nationwide network of engineers is trained to the highest standard in order to install security systems with a professional, efficient and reliable service.

DAS Technology are technology specialists with over a decades experience delivering solutions for both commercial and domestic customers. Their security division is full of specialists in CCTV, access control, door entry and fire.

Since its formation in 1989, Davies Security Group has been designing bespoke security systems for its clients from all areas of the marketplace. From standalone Fire, Intruder and CCTV systems to PC-based integrated solutions, Davies Security can provide for all specifications, incorporating the latest technology from the fast moving security sector designed individually to accommodate present and future security needs.

DC Solutions is a CCTV installer based in Luton.

de Jong SICHERHEIT & IT GmbH is an innovative system house for security, information and network technology and develops, among other things, intelligent solutions for hygienic access to buildings and rooms.

DEFENDERS, Inc. is a USA based security company that provides home security, safety and peace of mind to more than 2 million families in the US. They are focused on installing state-of-the-art security systems and providing post installation services.

With more than 100,000 professionals, Deloitte provides audit and assurance, tax, consulting, and risk and financial advisory services to a broad cross-section of the largest corporations and governmental agencies.

Delta Tec Alarms delivers high-quality alarm systems and reliable alarms to customers. The company advises customers on the products that best serve their security needs.

Denning Electronics has solved big communications, protection, and surveillance problems by providing sales and technical support to distributors, security system integrators, engineering design firms, architects, and system users. Their specialties include outdoor intrusion detection, video and audio surveillance, video/audio/data networks and transmission, access control, and ballistic/blast/chemical/acoustic barriers.

Dent Security Systems is the Cambridge security specialist. Founded in 1870 by locksmith Robert Dent. The company offers integrated solution of electronic and physical security to meet any circumstances in home or business premises. The service includes installation and maintenance of residential & commercial ‘burglar alarm’ systems, intruder alarm, remotely monitored intruder systems, police monitored burglar alarms, CCTV/ Video surveillance.

Destination 5 is a provider of access control, CCTV, intruder detection and advanced integrated Systems. The specialists work with government and public sectors is provided to support the foundation of our national infrastructure against security threat and to assist operative safety.

Direct Security provides Integrated systems, CCTV, access control, door entry, intruder alarm, fire systems, personal attack systems, photo-id, vehicle recognition ANPR, structured cabling, networked systems, asset management, project management, data management, software development, consultancy, and system auditing services. Direct Security is an ISO 9002 quality assured company and NACOSS Gold and Construction Line accredited.

Established in 1982 Direct Security Systems has earned an excellent reputation for providing security products and services in Wolverhampton, Walsall and surrounding areas in West Midlands. The company provides high performance intruder alarms, area detectors for residential, commercial & industrial needs, control panels that react to change, access control systems, card readers & keypads, CCTV & 24 hour monitoring services, fire alarm systems.

Domalarms is a family owned and run company. The company has its head office in Leeds on the outskirts of the city centre. Domalarms deals in all aspects of home, business and commercial security designing, supplying, and installation including burglar alarms, intruder prevention systems, CCTV systems, access control systems, automatic lighting, electrical services, fire alarms, and automated gates and barriers.

Domo Tactical Communications Broadcast is a global MNC engaged in the development, delivery and support of high-tech video surveillance, IP Mesh, Covert Audio and Video, integrated surveillance, maritime security and robotics solutions.

Dragon Fire & Security Systems is one of South Wales' largest independent fire and intruder alarm installers. The company offers intruder alarm, fire alarm, CCTV, remote monitoring (off-site), automatic gates and barriers, access control and door entry, emergency lighting systems' services. Dragon Fire & Security Systems is approved to all industry's highest recognised standards including NSI (NACOSS GOLD) and BAFEFire Alarm Certification Scheme.

DS Securities is one of the leading independent security and fire specialists in the UK. The company aims to provide a range of innovative, reliable and dependable security, fire, CCTV, access control, network and IP technology solutions, specifically designed, installed and maintained to highest standards for customer’s individual needs. DS Securities' clients include individual home owners, small businesses and large corporations.

dsc security is the trading name of DSC Alarms Ltd. The company is supplier and installer of security equipments to both Residential and Commercial customers. Based in Crowthorne Berkshire, dsc security is one of the premier privately owned security companies in the Thames Valley specialising in intruder alarms, locks, safes, CCTV & access control.

Cornwall CCTV, fire and security specialists, Duchy Alarms, offers a professional installation and maintenance service for a wide range of fire and security alarms and systems throughout the South West of England. Duchy Alarms has been serving the domestic and commercial industry throughout Devon and Cornwall. Previous clients include the RNLI, National Probation Service, and various Schools, Colleges, and NHS hospitals.

Dyfed Alarms Ltd is one of the largest independent suppliers and installers of intruder alarms, CCTV, fire detection systems and access control equipment in Wales. The company offers a wide range of security equipment and provides industry leading installation and maintenance services for both residential and commercial customers. Dyfed also offers 24-hour alarm monitoring and response, scheduled and emergency maintenance.