The ultimate guide to phone number validation  

Phone number validation plays a crucial role in identity verification and fraud prevention. Consumers expect brands to protect their digital privacy—87% demand strong security measures, and 38% would stop doing business with a company after a security breach. Additionally, two-thirds of consumers report that fraud incidents damage their trust and loyalty toward the brand.

Without validating phone numbers, businesses may face risks such as fraudulent accounts, failed communications, and potential regulatory compliance issues. To address these challenges, many companies rely on phone number validation services as part of their digital risk mitigation and identify verification process to authenticate customers, reduce fraud, and enhance customer experience.

Telesign’s Phone ID API provides a multi-layered approach to phone number validation, combining real-time data analysis, risk recommendations, and identity verification. By leveraging this technology, businesses can strengthen security, maintain customer trust, and prevent fraud before it happens.

This blog covers key topics related to phone number validation—from its importance and best practices to emerging trends and AI-driven advancements. We’ll also take a deep dive into Telesign’s phone number validation solution, its technical specifications, and how businesses across industries can integrate it seamlessly.

Table of Contents

• What is phone number validation? 
• Difference between basic validation, phone number intelligence, and risk analysis 
• Why businesses need phone number validation solutions 
• How Telesign’s phone number validation solution works 
• Technical specifications of Telesign’s phone number validation solution 
• The role of AI & machine learning in phone number validation 
• Key trends in phone number validation 
• What are the best practices for effective phone number validation?  
• What are the most common applications of phone number validation?  
  • E-Commerce and Online Marketplaces 
  • Financial Services and Fintech 
  • Enterprise Software and Saas 
  • Gaming and Entertainment  
• How to integrate Telesign’s phone number validation API? 
• FAQ

What is phone number validation?

Phone number validation is a type of identity verification that ensures that your customer can access the phone number they provide. It employs a multi-faceted approach to help assess the legitimacy and risk associated with a phone number.  

Key aspects of phone number validation include:  

These components are essential when businesses validate a phone number to strengthen identity verification and reduce fraud risks. 

How does phone number validation work?  

To verify phone numbers, the phone number validation process involves a series of checks to determine whether a phone number is legitimate, active, and reachable. The typical steps include: 

1. Format validation 

This step checks the phone number’s syntax, ensuring it follows the correct format for its country (e.g., correct number of digits, proper use of country and area codes). This is a simple, rule-based check. 

2. Number type identification 

Determines whether the number is a mobile, landline, VoIP, or toll-free number—an essential factor in  mobile identity verification.  

3. Luhn algorithm check  

Uses the Mod 10 Check, applying the Luhn algorithm (a checksum formula) to detect typos in number sequences.  While this method is primarily used for credit card validation, it can sometimes be applied to phone numbers that follow certain patterns. 

4. Carrier lookup (HLR/NP lookup) 

5. Reachability test (optional) 

Sends a short message to the number to confirm that checks whether the number has been ported from one carrier to another. 

Difference between basic validation, phone number intelligence, and risk analysis 

Let’s take a close look at what each of these terms means:  

Feature	Basic validation	Phone number intelligence	Risk analysis
Purpose	Ensure data accuracy and consistency	Enhance identity verification and fraud protection	Identify and manage organizational risks
Scope	Data quality checks	Phone number analysis for verification and fraud	Organizational risk management
Key techniques	Data type, range, and format checks	Phone number blacklists, carrier lookups, risk scoring	Risk identification and evaluation
Application	Forms, databases, client/server-side validation	Identity verification, fraud protection, authentication	Business operations, strategic planning

Why businesses need phone number validation solutions

Thwart fraud and enhance security

Help prevent identity misuse: Can reduce the risk of unauthorized accounts being created using stolen or fabricated identity information to create fake accounts or access sensitive information.

Support account protection efforts: It adds a layer of security that helps safeguard customer accounts from unauthorized access.

Identify unusual patterns associated with synthetic identities: Helps flag activity that may indicate the use of synthetic identities.

Reduce errors and boost data quality

Phone number validation is essential for maintaining the integrity of customer databases. By using phone number verify services, businesses can reduce communication errors, improve marketing effectiveness, and maintain a clean, accurate database.

As businesses receive phone numbers, verifying phone numbers ensures greater accuracy and overall data quality.

Streamline customer onboarding and improve overall experience

A seamless onboarding process is crucial for retaining customers and building trust. Phone number validation simplifies registration by confirming the legitimacy of user-provided numbers upfront, reducing unnecessary barriers and verification steps.

This helps ensure that genuine customers can quickly and efficiently create accounts, fostering a positive experience while maintaining robust security protocols. By removing delays and streamlining user interactions, businesses can strike the right balance between convenience and protection.

Meet compliance and regulatory needs

Adhering to applicable data protection laws and regulations is another key advantage of phone number validation.

These laws and regulations require accurate identity verification to safeguard sensitive information. Phone number validation helps businesses meet these standards by verifying customer data integrity, avoiding fines, and promoting trustworthiness in global markets.

This compliance not only mitigates legal risks but also reinforces a company’s commitment to secure operations.

Enhance operational efficiency and reduce cost

Fraudulent activities often result in costly chargebacks, disputes, and additional security measures. By incorporating phone number validation, businesses can reduce the likelihood of these issues.

Validating numbers minimizes resource allocation for manual remediation efforts and supports fraud mitigation processes, allowing companies to optimize their budgets while maintaining efficient workflows. This preventative strategy supports both long-term sustainability and enhanced profitability.

How Telesign’s phone number validation solution works

Here are the key features of Telesign’s Phone ID API for phone number validation:  

Risk recommendations help businesses to prioritize security measures and allocate resources effectively, focusing on the most suspicious numbers. 

Technical specifications of Telesign’s phone number validation solution

API availability 

REST API for seamless integration that enables seamless integration with existing systems, allowing businesses to incorporate phone number validation into their workflows easily. It facilitates rapid deployment and scalability across various applications. 

Response time 

Real-time processing within milliseconds ensures that phone number validation does not delay customer onboarding or transaction processing, maintaining a smooth user experience. It supports high-volume transactions and rapid decision-making processes. 

Data sources 

Carrier databases, global numbering plan data, and ML models. Combines diverse data sources to provide comprehensive insights into phone number legitimacy and risk. 

Integration options 

It supports JSON and XML responses for flexible deployment by integrating them with different systems and programming languages, making it easier for developers to deploy the solution. It accommodates various technical environments and development frameworks. 

Security and compliance standards 

AES-256 encryption for secure data transmission and compliance certificates such as SOC 2 compliance and ISO 27001 certification. It helps to protect sensitive data during transmission and storage, adhering to rigorous security standards. 

The role of AI & machine learning in phone number validation 

AI and machine learning play an increasingly important role in the future of digital fraud prevention by enhancing phone number validation.  These technologies support risk detection, improve fraud protection, and strengthen customer identity verification software. Here’s how AI and ML are transforming phone number validation: 

AI-powered analytics for improved risk detection 

AI-powered analytics play a crucial role in enhancing risk and fraud detection by analyzing vast amounts of data associated with phone numbers. Many customer identity verification software solutions already incorporate these systems to enhance security.  

AI models can identify patterns that may indicate fraudulent activity, such as unusual call behavior or sudden changes in phone number usage. By recognizing these anomalies, businesses may proactively detect and mitigate risks. 

Behavioral analytics in phone number risk recommendations 

Behavioral analytics involves analyzing user behavior patterns linked with phone numbers to analyze potential risks. This includes monitoring call activity, messaging patterns, and other usage metrics to detect suspicious behavior.  

ML models for continuous adaptation 

ML models are designed to evolve and adapt to changing patterns in user behavior.  By learning from historical data and continuously updating their algorithms, these models stay ahead of emerging threats. As fraud tactics become more sophisticated, ML-driven systems can quickly recognize and respond to new attack patterns, ensuring ongoing security in verifying a phone number. 

Future of identity verification with AI-driven phone intelligence 

 AI-driven phone intelligence is expected to continue to shape the future of customer identity verification software, offering more advanced fraud detection capabilities. Some key developments to expect include:  

Key trends in phone number validation

Here are the key trends shaping phone number validation in 2025: 

AI-driven fraud prevention: Artificial intelligence is becoming essential in fraud prevention strategies. It enhances phone number validation by enabling smarter, faster risk assessment and helping businesses detect suspicious activity before it escalates. 

Passwordless authentication as the new norm: With a growing emphasis on frictionless user experiences, passwordless authentication—often powered by phone verification—has become a standard part of mobile identity verification APIs. It offers both convenience and security in a single step. 

Rise in phishing and social engineering tactics: As digital threats become more sophisticated, phishing attacks are increasingly targeting mobile communication channels. This may encourage businesses to strengthen their phone number validation workflows to protect user accounts. 

Emphasis on mobile security awareness: Organizations are prioritizing education and awareness efforts to help users recognize and respond to threats. Phone number validation plays a supporting role by flagging potentially risky numbers and preventing exploit attempts. 

Regulatory pressure shaping verification standards: Global regulations are driving businesses to reassess and improve how they verify a phone number. Compliance requirements now demand greater accuracy, transparency, and accountability in digital identity verification practices. 
 
Wider adoption of mobile identity verification APIs: Businesses across sectors are integrating mobile identity verification APIs into their platforms to reduce fraud, enhance onboarding, and build long-term user trust. 

Challenges from number spoofing and virtual numbers: The rise of VoIP and number masking technologies has made fraud detection more complex. This has led to broader adoption of advanced phone number validation to uncover anomalies and protect against spoofed identities. 

Shift toward proactive security strategies: Instead of reacting to breaches, businesses are building proactive defenses by layering phone number intelligence, risk analysis, and real-time monitoring into their verification processes. 

These trends in phone number validation reflect the evolving needs of both users and businesses—and the growing importance of secure, intelligent identity verification in today’s digital ecosystem. 

By staying ahead of these trends, businesses can leverage Telesign’s Phone ID API to validate phone numbers and ensure compliance, security, and seamless customer interactions. 

What are the best practices for effective phone number validation?

Following best practices is essential to check if a phone number is valid and ensure accuracy in your verification process.  

What are the most common applications of phone number validation?

Here are the top use cases and case studies of phone number validation that Telesign delivered successfully across the following verticals:  

E-Commerce and Online Marketplaces

Case study #1: AstroPay Improve customer onboarding and Reduces Fraud 

Here are the use cases for AstroPay: 

AstroPay successfully increased the ratio of active accounts while optimizing promotional costs by reducing fake accounts. Also, with Telesign’s SMS API offering a comprehensive digital identity verification solution, the company achieved better SMS deliverability, ensuring timely communication with customers. 

Financial Services and Fintech

Case Study #2: Amount streamlines onboarding and verification 

Here are the use cases for Amount: 

By leveraging Telesign’s technology, Amount improved the efficiency of onboarding new customers while reducing the risk of fraudulent account creations. This ensured a smoother and seamless experience for both businesses and their users. 

Enterprise Software and Saas

Case Study #3: Salesforce enhances account security 

Here are the use cases for Salesforce: 

Salesforce improved its security infrastructure, reducing instances of unauthorized account access. This integration significantly strengthened platform security, providing users with a more secure and seamless experience. 

Gaming and Entertainment

Case Study # 4: Ubisoft ensures secure gaming experiences 

Here are the use cases for Ubisoft: 

By integrating Telesign’s security solutions, Ubisoft significantly enhanced the security of gamer accounts, creating a safer gaming environment. This implementation reduced fraudulent transactions and protected players from unauthorized access. 

How to integrate Telesign’s phone number validation API?

Integrating Telesign’s Phone Number Validation API into your systems is a straightforward process that helps enhance security and reduce fraud risks.  

Businesses can seamlessly integrate this robust solution to verify phone numbers globally by following these simple steps. 

Step 1: Sign up for API access 

Start by registering on portal.telesign.com to obtain API access. After creating your account, you will be provided with a Customer ID and API key, which are essential for integration. 

Step 2: Retrieve your API key 

Once your account is active, log in to your developer dashboard to retrieve your unique API key. This key will authenticate your requests to the API. 

Step 3: Make an API request 

Telesign’s API supports multiple programming languages, including Python, Java, and PHP, allowing developers to work with their preferred frameworks.  

You can send an API request using the REST interface to validate a phone number’s format, carrier, type, and more.  

Step 4: Interpret the response 

The API returns detailed data, including whether the number is active, its type (mobile, VoIP, or landline), and its associated carrier. It also provides a risk score to flag potentially fraudulent numbers.  

Use this information to make informed decisions about customer onboarding and security protocols. 

Step 5: Implement risk-based decision making 

Utilize the validation results to create customized workflows. For instance, block high-risk numbers, request additional verification for suspicious accounts, or approve genuine numbers for seamless onboarding. 

Telesign’s API ensures businesses can check if a phone number is real while adhering to international privacy regulations.  

It supports global validation, making it an effective solution for preventing fraud and improving security.  

With Telesign, businesses can confidently differentiate between phone number validation (checking functionality) and verification (proving ownership). 

Telesign’s Phone ID API offers an advanced phone number validation tool powered by AI-driven risk assessment, ensuring mobile number verification and enhanced fraud protection. 

FAQ