SignalHire: Verified Candidate Contact Data, Explained

TL;DR: SignalHire is a contact discovery platform for recruiters and sales teams that verifies email addresses and phone numbers in real time at the moment of search, rather than serving them from a static list. It covers 850M+ profiles and 30M+ companies, claims 95%+ email accuracy with a 3–5% bounce rate, and returns both email and phone from a single lookup. This article explains how it works, what the numbers actually mean, who it fits, and where a recruiting firm would be better served by something else.

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Who this article is for

This is for recruiting firms and internal talent acquisition teams sourcing at volume, roughly twenty or more candidates a month, who are still working outbound by hand. If your sourcers are guessing email formats, running profiles through two separate tools to get an address and then a phone number, or burning InMail credits because they cannot reach people any other way, the bottleneck is contact data, not process.

It is also for sales and revenue teams doing the same work under a different name. The mechanics of finding a verified mobile number for a hiring manager and finding one for a buyer are identical.

It is not for you if you place fewer than five searches a month, where manual research and a free InMail allowance genuinely suffice, or if you hire entirely from inbound applicants and never need outbound discovery. A contact database solves a problem you do not have in either case.

The problem with contact data

Every contact database ages. A profile that was accurate when it was scraped decays as people change jobs, companies migrate email conventions, and numbers get reassigned. The industry standard response is to re-crawl on a schedule and hope the gap between crawls is small enough not to matter.

That gap is where a sourcing team's time actually goes. A bounced email is not just a wasted send; it is a wasted sequence slot, a damaged sender reputation, and in aggregate a deliverability problem that quietly reduces the response rate on every other message the team sends. Bounce rate is not a data quality metric. It is a channel health metric, and it compounds.

The design decision that separates contact tools is therefore not database size. It is when verification happens. A tool that verifies at crawl time is telling you an address was valid at some point. A tool that verifies at search time is telling you it is valid now.

How SignalHire works

SignalHire verifies contact details in real time when you run the lookup, and returns both a work or personal email and a phone number from a single search. Coverage is stated as emails for up to 90% and phones for up to 80% of people, against a database of 850M+ profiles and 30M+ companies that is refreshed every 7–10 days.

The accuracy figures the company publishes are 95%+ email accuracy with live verification, a 3–5% bounce rate, and an 85%+ hit rate on social media profiles.

Read those two sets of numbers together, because they mean different things and are easy to conflate. Coverage tells you how often the platform finds anything at all for a given person. Accuracy tells you how often what it found is correct. A tool can score well on one and badly on the other, and only the combination predicts what your sourcers actually experience.

Contact Finder and bulk enrichment

The core workflow is a lookup that returns verified details for an individual, with bulk enrichment processing up to 1,000 people per run. For a firm working a shortlist rather than a single req, the bulk path is the one that matters, and 1,000 per run is a sensible batch size for a weekly sourcing cycle.

Database search

The searchable database filters by name, title, company, and location, and exports up to 1,000 profiles or companies at a time. This is the "build me a list" path as opposed to the "enrich this list" path, and most teams end up using both.

Browser extension

A Chrome and Firefox extension runs lookups directly on profile pages, and works across LinkedIn plus Facebook, GitHub, Twitter, and other sites. GitHub coverage is the quietly useful one for technical recruiting, where the strongest candidates often have a sparse LinkedIn presence and an active repository history. Installing the extension adds 10 free credits each month.

Email sequences

SignalHire includes multi-step cold email automation with tracking and rules, sending through Outlook, Office 365, or your own company domain. This makes it possible to run discovery and first-touch outreach without a second tool, though teams already running a dedicated sequencer will likely keep it and use SignalHire purely as the data layer. Our guide to automating lead follow-up covers what a good follow-up cadence looks like regardless of which tool sends it.

API and integrations

There is a Person API and a Search API with REST endpoints, API-key authentication, credit balances returned in response headers, and documented rate limits. That last detail is worth more than it sounds: undocumented rate limits are how integrations break in production at the worst possible moment.

More than 25 CRM and ATS integrations are listed, including Salesforce, Zoho Recruit, and Pipedrive. Verify yours specifically before buying. "25+ integrations" is a marketing number; the only one that matters to you is whether it writes cleanly into the system your recruiters actually live in.

Reading the numbers honestly

Two notes on interpreting this table. First, "up to" is doing real work in the coverage rows, as it does on every vendor site in this category. Up to 90% is a ceiling, not an average, and your realised coverage depends heavily on geography and seniority. Second, a 3–5% bounce rate is genuinely good if it holds on your list, and it is trivially cheap to test.

Which is the entire point: do not take any of these numbers on faith, including ours. Run a sample.

How to test it before you buy

Take 200 real profiles from a live requisition, not a curated test list and not your best-known accounts. Include the awkward ones: candidates outside your primary country, people at companies under 50 headcount, and at least a few profiles with minimal LinkedIn activity. Then measure four things:

1. Hit rate. What percentage returned any contact detail at all?

2. Phone-specific hit rate. What percentage returned a usable phone number, measured separately from email? These diverge more than most teams expect.

3. Bounce rate. Send to the emails and count hard bounces. Compare against the published 3–5%.

4. Connect rate. Call a sample of the numbers. A valid-format number that reaches a disconnected line is not a valid number.

Run the identical list through whatever you use today. The comparison you need is not SignalHire against its own marketing; it is SignalHire against your current stack, on your candidates. Our roundup of candidate sourcing tools for recruiting firms covers the alternatives worth putting on the other side of that test.

Fitting it into a sourcing workflow

Buying the tool is the easy part. The teams that get value out of a contact platform tend to structure the work in the same way, and it is worth designing this before the first credit is spent.

Split discovery from enrichment. Building a list and enriching a list are different jobs with different failure modes, and running them as one blurred activity is how credits get wasted. Use database search to build a targeted list, review it for fit before spending anything on contact details, then enrich in bulk. Reviewing first sounds obvious and is skipped constantly.

Decide where the record of truth lives. If contact details are pulled into the extension and then pasted into an ATS by hand, you have automated the lookup and left the transcription error in place. Either the integration writes into your ATS or the API does, and that decision should be made before rollout rather than six weeks in.

Budget credits against requisitions, not against people. A recruiter who knows a req is worth 200 enrichments works differently from one who is told to be careful. Vague instructions to conserve credits produce hoarding, and hoarding produces sourcers who go back to guessing email formats, which is the behaviour you were paying to eliminate.

Ask directly about the credit model before signing. How is a credit consumed when a lookup returns an email but no phone? What happens when it returns nothing at all? Do unused credits roll over? These answers materially change the effective cost per usable contact, and they are not always on the pricing page. Ask in writing.

Finally, set a re-verification rhythm. Even a real-time verified number decays once it is sitting in your ATS. A contact detail captured six months ago is a historical record, not a current one, and treating it as current is how a clean database quietly rots.

Where SignalHire fits, and where it does not

It fits teams sourcing at volume that need email and phone together and are tired of paying for two tools to get them. It fits technical recruiting, where the GitHub and multi-site coverage reaches people who are effectively invisible on LinkedIn alone. It fits any team whose current bounce rate is high enough to be hurting deliverability, because real-time verification is a direct fix for that specific problem.

It fits less well if you need deep ATS-native sequencing and reporting as one system. The sequencing exists, but a firm running sophisticated nurture campaigns will likely keep its dedicated platform and use SignalHire as the data source feeding it. That is a reasonable architecture, not a failure, but it changes the cost calculation because you are then paying for both.

It also fits poorly if your sourcing problem is actually a targeting problem. If your team can already reach people and simply is not getting replies, better contact data will not help. That is a messaging and list-selection issue, and buying a database to solve it just gets you to more of the wrong people faster. The same logic applies to AI agents in recruiting — automation multiplies whatever your process already is, in both directions.

Frequently asked questions

What makes real-time verification different?

Most databases verify when a record is crawled and serve it until the next crawl. SignalHire verifies at the moment of search, so the answer reflects current state rather than the state at last crawl. This is the mechanism behind the low bounce rate claim.

Does one lookup return both email and phone?

Yes. Both come back from a single lookup, which is the main reason teams consolidate onto it from separate email and phone tools.

How current is the underlying data?

The database is stated as refreshed every 7–10 days, with live verification applied on top at search time.

Does it work outside LinkedIn?

Yes. The browser extension supports Facebook, GitHub, Twitter, and other sites in addition to LinkedIn, which matters most for technical roles.

Can it push into our ATS?

More than 25 CRM and ATS integrations are listed, including Salesforce, Zoho Recruit, and Pipedrive, plus a documented REST API for anything not covered natively. Confirm your specific system before committing.

What is the bulk limit?

Enrichment runs up to 1,000 people at a time, and database exports run up to 1,000 profiles or companies at a time.

Where to go next

If contact data is genuinely your bottleneck, the fastest way to find out whether SignalHire fixes it is the 200-profile test described above, run against your current tooling on a live requisition. It takes an afternoon and it answers the question that no vendor page can.

You can start at SignalHire, and the browser extension is the low-commitment way in, since installing it adds 10 free credits a month and lets a sourcer try it on real profiles before anyone signs anything.