Historically no one authority was responsible for collating all telephone numbers within the UK.
BT was the main source of telephone number information, but their data did not include all telephone numbers from other telecommunication companies.
In 1999 an independent body called The Directory Solutions Unit was formed to collate telephone number information from nearly all UK Telecom's Providers, including
BT
Kingston-Upon-Hull Communications
Cable Companies
Mobile Phone Providers etc
Directory Solutions are responsible for collating all changes to UK Telephone Numbers - the database is called BT OSIS, which stands for the 'Operator Services Information System'.
Licensed bureaux such as ADMAR are permitted to hold a copy of the database on-site, thus having instant and unlimited access to every available UK phone number. We are also licensed to access the Ex-Directory section of the database and DQR Numbers.
NB.Some companies with full page adverts, National Numbers etc are missing from the OSIS Database.
The service is funded by licence holders paying a Royalty fee for each search.
A daily file is issued by OSIS containing between 30,000 - 100,000 additions, deletions or amendments making the file The Only Up-To-Date and most Comprehensive source of Telephone Number Information in the UK.
ADMAR add telephone numbers to client's databases using an Automatic Computer Matching Process.
