2025 Caller Authentication Guide for Contact Centers

With all the information available online, you’d be tempted to think people wouldn’t be so quick to turn to the phone when they have an issue with a device or other products. Research shows a different story, with 68% of customers still prefer calling when they need help. Most callers are genuine, but the risk of fraud is not something to overlook, especially with audio deepfakes becoming increasingly sophisticated.

But how can you tell who’s genuine and who isn’t? After all, passwords, PINs, and security questions can be stolen. Caller authentication solutions address this issue by combining different techniques that increase contact center security and help determine that the caller is who they say they are.

What is caller authentication?

Caller authentication verifies a caller’s identity before granting access to sensitive account information or completing specific transactions.

In a contact center environment, authenticating a caller is essential to protect against the potential for fraud, safeguarding customer data, and maintaining compliance with regulatory standards. In simple terms, caller authentication is a layer of security that verifies that the caller is who they claim to be.

Why caller authentication matters in 2025

Many people use online transactions and remote interactions daily. Besides common scams and identity theft attempts, for a few years now, we’ve also been witnessing the rise of something more troublesome: deepfakes. This technology uses AI and deep learning algorithms and can mimic someone’s appearance and voice.

Deepfakes have become so sophisticated it is almost impossible for humans to tell the difference. Thankfully, voice recognition software can still spot synthetic voices. When used alongside other caller authentication techniques, they can help spot fraud.

Plus, regulations such as the GPDR in the EU or the CCPA in California, US, require strict data protection, which extends to contact centers, as they typically process a lot of personal data. Proper authentication also instills customer confidence, showing them that measures are taken to protect their data.

Types of authentication methods

Understanding the types of authentication methods can help contact centers choose the right tools to meet security needs without disrupting the customer experience.

Multi-factor authentication (MFA)

Multi-factor authentication (MFA) combines two or more authentication techniques to verify a caller’s identity.

The most common method is combining a password with an OTP sent via SMS or email. That way, if someone steals a person’s password, they won’t be able to access the account, as the system will ask for a secondary form of authentication.

Knowledge-based authentication (KBA)

Have you ever needed to set up a security question for an account? This is known as knowledge-based authentication (KBA).

The questions usually involve answers that anyone can easily find, like your mom’s maiden name, your birth city, or your pet’s name. While this may seem secure, especially in combination with a password or other form of authentication, it has serious limitations.

The answers are often easy to guess by people in a person’s inner circle, and with social media, many people inadvertently share those answers at some point.

Biometric authentication

Biometric authentication, such as voice recognition or fingerprint scanning, uses physical or behavioral traits to confirm identity.

Voice biometrics, in particular, is popular in contact centers. It analyzes vocal patterns to determine identity. It’s a secure and user-friendly option that requires an initial enrollment process.

Token-based authentication

In token-based authentication, callers are given a token, often an OTP or hardware token, to verify their identity.

Tokens are generally temporary and time-sensitive, providing high security with minimal inconvenience. For contact centers, token-based authentication is often used alongside other methods for added security.

ANI validation and ANI match verification

ANI validation is a common caller authentication technique that requires no user input. Here’s how it works.

What is ANI?

ANI stands for automated number identification, a telecommunications technology that displays the caller’s number to the recipient. It is the backbone for many caller authentication methods, helping identify the number associated with a particular call.

ANI validation

ANI validation helps confirm that the call comes from the device that owns the number and isn’t spoofed or manipulated. It is a passive process before the agent picks up the call, so it doesn’t disturb the conversation, improving a customer’s experience.

ANI match

ANI match compares the incoming number with numbers stored in the customer’s account history. This adds a layer of security and can be part of an effective multi-factor authentication strategy.

Like ANI validation, it’s a passive authentication method that requires no action from the caller. This makes it easy for businesses to personalize the call on the spot, as they can know when a customer is calling, what products they are using, and more.

The threat of spoofing

Call spoofing erodes confidence in the Caller ID system by enabling the caller to manipulate the ANI. Criminals frequently use this tool to replace their caller ID with a genuine customer’s number. Companies that cannot detect call spoofing are at risk of verifying calls from impostors.

Combining ANI validation and ANI match can combat spoofing. First, you’ll make sure the number hasn’t been changed or manipulated. Then, once you see it is most likely genuine, you’ll check it against your customer database. This technique is a lightweight, passive solution to fighting against spoofing.

Understanding caller authentication enrollment

Caller authentication sounds great in theory, but you’ll need to enroll your customers in the process for most techniques. You need to gather data and permissions to enable technologies like voice biometrics or token-based systems.

For instance, enrolling in voice authentication may involve capturing vocal characteristics that the system can later use for verification. Enrollment must be secure and straightforward to encourage adoption and ensure smooth future interactions.

Remember data privacy and security. While many customers will be happy to help you make their account more secure, some might feel uneasy about revealing their voice. You must be prepared to explain the process, including how you plan to store and secure their data.

Ideally, you should also have a backup plan for customers who will reject such a method. MFA, KBA, or token-based methods will be useful in this case. ANI validation and ANI match are also methods that will work for most customers.

How does phone call authentication work?

With phone call authentication, you have two options: passive and active authentication.

Passive authentication

Passive authentication means authenticating callers without any interaction from them or the agent. The process usually takes place before the agent and caller are connected.

It creates a smoother experience for both the agent and the caller as they can focus on their discussion right away without stopping to go through a lengthy verification process.

In some instances, passive authentication can also happen during calls through continuous voice biometrics, often used to reduce the risk of deepfakes.

Active authentication

Active authentication requires the caller and agent to take part actively. The caller often has to enter a PIN or a password, or the agent might ask certain security questions. MFA, KBA, and token-based methods are well-known active authentication techniques.

Active and passive authentication methods may be combined in environments that work with sensitive data, such as the healthcare system.

What is the caller authentication process?

The caller authentication process generally involves three stages: initiation, verification, and approval or denial. During the initiation phase, the caller dials into the contact center, and their information, such as the phone number, is identified.

Enrollment optimization plays a vital role in this phase, simplifying the initial setup of caller authentication to maximize efficiency for customers and the business. Enrollment can be passive, where no input is needed from callers or agents, or active, where callers must provide information.

Passive enrollment is ideal because it doesn’t require caller involvement, creating a smoother experience. This approach boosts the efficiency of the authentication process, as every caller enrolls easily, allowing the system to recognize them quickly when they call. This minimizes customer effort, improves brand loyalty, and ensures a positive experience at every step.

During the verification phase, the system checks the caller’s identity using one or multiple authentication techniques. If using an active authentication method, an agent will usually need to pick up the call to ask for the PIN or security questions. However, some companies have started using AI to cover this step.

Based on the verification outcome, the caller gains access or is denied entry to sensitive account data.

Implementing an optimal, passive caller authentication process

A passive caller authentication process is easier and faster for customers and agents. But how to create one? Here are a few steps to consider.

Assess your current system

Before implementing any new authentication method, evaluate your current system’s strengths and weaknesses. Identify gaps in security and user experience, focusing on areas where you can enhance authentication without causing delays or discomfort for callers.

Choose the right authentication method

Select an authentication method based on your customer base and security needs. For example, voice biometrics may be ideal for a high-volume center, while ANI validation and ANI match can help address spoofing.

Integrate authentication solutions

Integrate chosen solutions into your existing infrastructure, ensuring that different systems (CRM, IVR, etc.) work together smoothly. Integration should also allow for flexibility, as future changes in authentication methods may arise.

Best practices for effective caller authentication

Setting up the caller authentication process is not the end of the road. It is not something you can set up and forget about. You must follow a few best practices for genuinely effective caller authentication.

Ensure accuracy and efficiency

Effective caller authentication minimizes customer wait times while ensuring high accuracy. Monitor your system’s performance regularly and optimize as necessary.

You can also try asking for feedback after a call from both customers and agents. Notice if any part of the authentication process seems challenging or tedious and how you could improve it to make it a better experience for everyone involved.

Regular updates and maintenance

Cybersecurity threats are never stagnant, so your authentication systems need regular updates. Ensure that your methods and technologies are up-to-date to counter emerging fraud tactics.

Customer education

No matter how good your authentication process is, it won’t help if customers are reluctant to enroll or misuse it by sharing passwords and other details.

Tips for optimizing enrollment for enhanced authentication right now

A good caller authentication strategy requires an optimized enrollment process. Here are a few practical tips to streamline enrollment, making authentication faster, more reliable, and user-friendly for customers and contact center teams.

1. Leverage ANI as a factor in the ID claim

ANI can serve as a primary factor in your ID claim process. By matching the ANI with registered data, you reduce the reliance on more intrusive authentication methods while helping prevent spoofing and other scams.

2. Leverage a unique identifier

Use unique identifiers, like account numbers or customer IDs, to strengthen the authentication process further. It is a passive method that authenticates the caller in the background, so the agent and the customer can immediately focus on their call.

3. Avoid clunky active enrollment

Active enrollment, where the caller needs to answer questions or remember complex passphrases, is time-consuming. When calling, a customer just wants to have their issue solved without going through the hassles of authentication.

Make the enrollment process simple and intuitive to avoid frustrating customers. Complicated enrollment deters adoption and may lead customers to abandon authentication altogether.

4. Keep things simple with API integration whenever possible

APIs can help integrate authentication solutions across platforms, making adding or upgrading security measures easier without disrupting the customer experience.

For instance, Pindrop’s APIs come with a simple integration process and are leveraged across both the agent’s and the IVR’s portion of the call.

5. Engage experts

Bringing in experts to advise on the latest authentication tools and practices ensures that your center has the most effective, efficient security measures.

Enhance your contact center authentication systems today

Investing in caller authentication is more than security; protecting your brand and ensuring customer loyalty.

If you’re looking for a comprehensive solution, Pindrop^® Passport might be the correct answer. Designed to improve caller authentication with advanced, passive technologies, it secures interactions without disrupting the customer experience.

By understanding the different types of authentication, implementing best practices, and focusing on ease of enrollment, your contact center can offer a secure and smooth experience in 2025 and beyond.