Choosing a Verification Partner: What We Learned from Evaluating 10+ Phone Verification Providers
Phone data is only valuable when you trust that a number is active, accurately classified, and connected to the right person.
As one of the world’s largest contact intelligence platforms, phone data has always been critical to RocketReach. That’s why we took on a major investment to improve the quality of our phone offerings. This involved evaluating more than ten phone verification providers across coverage, accuracy, and scalability.
Why Phone Verification Is Harder Than It Looks
Phone verification is more than a simple “valid” or “invalid” label. Validity is an important component, but you also need to understand a phone number’s line type to inform your outreach strategy. It’s also critical to know whether a number is actually associated with the correct person.
Many popular phone verification solutions only address one or two of these areas. For example, a provider may tell you a phone number is an active landline, but offer little to no information about who actually owns that number. This leaves you, or your team, with the job of figuring out whether a number is worth calling.
Staleness is another major challenge. Some solutions heavily rely on information from a phone number’s original assignment. However, phone numbers can be ported between carriers, and line types change over time, making older data unreliable.
On the other hand, solutions may rely on sources such as caller name (CNAM) lookups for identity information. These are primarily U.S. focused, offer limited identity coverage, risk having stale information, and provide little insight into whether the number is still active.
Finding a solution that reliably handles all three areas – phone validity, line type accuracy, and identity matching – while also providing strong global coverage proved to be a significant challenge.
What We Looked for in a Partner
When evaluating partners, we focused on three core areas:
- Line type: Is this a mobile phone, or another type?
- Validity: Is the phone number currently in service, or has it been disconnected?
- Identity matching: Is the phone number actually associated with the person we expect it to be?
Beyond data quality, we also had significant technical requirements. Not only did we need someone who could verify 190 million phone numbers upfront, but we needed a partner that could support ongoing verification as our data changes.
RocketReach identifies new phone numbers during live contact lookups, so real-time support was non-negotiable. More specifically, we needed a partner capable of supporting real-time verification without creating unnecessary latency for our customers.
Finally, we wanted a long-term partner that we could trust and scale with as our phone data offering grows.
How We Tested Providers
We considered more than ten providers based on market research, prior experience, product capabilities, and scalability. To evaluate them, we built multiple datasets where we already knew the expected results.
We leveraged RocketReach’s Data Co-op of nearly 1.5 million active members to create a sample of known valid phone numbers, along with separate datasets of known invalid numbers. We also made sure our samples included a mix of geographies and line types so we weren’t testing against one type of phone data.
Using these datasets, we evaluated results from each provider across our three key areas: phone validity, line type accuracy, and identity matching. After months of testing across multiple datasets, it became clear that there are significant differences between the phone verification tools available today.
Key Takeaways From Testing
- Stale phone data is unreliable.
Many phone verification providers may share information from a number’s original carrier. Not their current one. For example, a number originally assigned to a landline and later ported to a mobile phone would still appear as a landline number. Relying on original assignments can result in inaccurate phone data, making it critical to use the latest information available.
- Identity matching is where many providers fall short.
A provider may correctly determine a number is active, but provide little confidence that it actually belongs to the person you are trying to reach. It offers little value, especially for professionals looking to connect with their next lead.
- Providers often disagree on whether a number is valid.
A phone marked “valid” by one provider may be marked “disconnected” or “unknown” by another, usually when providers rely on stale signals. This made it important for us to test providers against known outcomes.
Why We Chose Trestle
Through months of testing, Trestle consistently performed at the top across our criteria.
Trestle delivered the strongest overall combination of phone validity, line type accuracy, identity matching, global coverage, and scalability. Our research even found that contacts with Trestle-verified numbers are twice as likely to result in successful connections compared to contacts that have not been verified yet.
Just as importantly, we developed confidence in their team and technology as a long-term partner that could support RocketReach at our scale. That combination ultimately made Trestle the right choice for us.
Moving forward, RocketReach will use Trestle’s Real Contact API and Phone Validation API to verify 100% of our new and existing phone numbers. Identity matching is one of the key signals RocketReach uses to assign A, A-, and B confidence grades to contact data. Now, with the Real Contact API, we can extend identity matching to our phone offering, and build confidence in our ability to match phone numbers to the right people. The Phone Validation API also gives us global coverage so we can validate international phone numbers and assign accurate line types.
By partnering with Trestle, we can go the extra mile for our customers by offering pre-verified phone numbers at no additional cost. This partnership is the first of many continued investments in our lead intelligence, and we look forward to strengthening our database alongside Trestle.
This blog post was written by Jamie Gullbrand, Head of Data at RocketReach.
