Mobile Number Validation using Tall Bob API

Tall Bob allows API users to validate mobile numbers using the endpoint Mobile Lookup. The mobile number provided is validated and then queries using an HLR request (Home Location Register). The main advantage of using this endpoint is to ensure message deliverability.

What is HLR?

HLR stands for Home Location Register, a database maintained by mobile network operators that stores information about subscribers and their phone numbers. Verifying mobile numbers can help companies improve the accuracy of their customer data, reduce costs associated with undeliverable messages, and prevent fraud. 

Mobile Number validation is done for three major scenarios:

Checking Number Length and Format

This is done by validating the IMSI of the provided mobile number. This is done to ensure that the mobile number is entered correctly into the system. The IMSI is a 15-digit number that carries information about the country code, network code and subscription identification number

IMSI (International Mobile Subscriber Identity) = MCC (Mobile country code) +MNC (Mobile network code) +MSIN (Mobile Subscription Identification number) 

Checking Number Portability

This type of validation is done to check for scenarios where the subscriber decides to keep the old number but move to a different operator

Checking if the number is in Roaming

This validation is essential as this would help in preventing fraudulent actions towards the user’s accounts

Common use cases

The common cases that would require the use of the mobile number validation endpoint would be:

1. To fix bad formatting and numbers

2. To validate what numbers are still live 

3. To enrich your database with accurate and complete mobile information.

How is it done?

1. The user inputs a mobile number in the endpoint Mobile Lookup to verify the number.

2. The API returns a response with ‘true or false’ to confirm if the Mobile number is Valid

3. if the number is invalid, it will include a reason in the 'Status' field

Error Messages

The status value is ‘Invalid’ when:

1. The mobile number entered is too short

2. The number is invalid

3. The subscriber is unknown/absent

4. The service is restricted by the destination network etc.