Free Data Audit

Telephone Number Appending

OSIS Telephone Number Appending and Verification

Although mailings and emails are very useful and convenient ways of keeping in touch with your customers, nothing beats the effectiveness of a personal telephone call. When a representative from your company talks to prospective customers, you build a personal bond of trust with them.

However, there are many instances where you do not have access to a contact telephone number. BT's OSIS telephone number appending and verification service is provided in house by Data Cleansing Services and can be used to provide up-to 3 telephone contact numbers.

What we actually do

We run a thorough check of each contact by matching the names and addresses with BT's telephone directories and identify the phone numbers that are either entered incorrectly, not functional or changed.

We use the Operator Services Information System (OSIS) to append your list with the correct numbers.

OSIS is more cost effective when compared to other sources. Consequently, you can hire us and get your database appended very affordably. Using OSIS also has other advantages.

  • Presence of complete contact details including full name, address and phone numbers ensures more than 95 percent accuracy when we append and verify numbers
  • The file is updated every day. No other source is as up to date as OSIS
  • The file includes landline as well as mobile numbers
  • OSIS contains phone numbers that are stored as ex-directory. These numbers do not appear in your local telephone directories

The ex-directory flagging feature is extremely useful because the database not only gives access to hidden numbers, but also lets you know that these customers are not interested in divulging their numbers and hence, are not very likely to respond to telemarketing.

Why hire us

We are efficient. See our testimonials page. With a number of years of experience in data verification and cleansing, we know the various legal routes through which phone numbers can be verified.

You can trust us. Every one of the customer databases that our customers give us for verification is strongly encrypted and protected. So, you can be sure that your database will not suffer security breaches. We do not sell, share or use details from your database for any other purpose and under any circumstances.

Contact us today for professional, reliable and affordable OSIS telephone number appending and verification service.


Upload your file(s) now for your FREE audit to check the current health of your database and
start saving money today.

Alternatively, call us now on 0208 481 9466 and one of our operators will be pleased to help.