Candidate contact data is the least glamorous part of sourcing and the most decisive. A shortlist you cannot reach is not a shortlist, and the gap between a 60% contactable rate and an 85% contactable rate removes a quarter of your pipeline before a single message is written. No amount of message testing recovers that.
This guide covers what each data type is actually worth in recruiting, where providers get it, how to test coverage properly before you buy, and the legal obligations that attach the moment you hold someone’s personal number. The compliance section is not optional reading — mobile data in particular carries genuine financial exposure in the United States.
Why candidate contact data decides your funnel
Recruiting has a data problem that sales does not. In sales, your prospect stays at the company you found them at, and their work email keeps working. In recruiting, the most valuable candidates are precisely the ones who move — and the moment they move, the work address you stored becomes worthless.
Worse, that decay is invisible. A talent pool built eighteen months ago looks full in your system while a third of it is unreachable. Teams routinely discover this only when a campaign returns a 15% bounce rate and their sending domain starts landing in spam folders.
The fix is structural rather than heroic: prefer data types that survive job changes, verify before sending, and measure contactability as a first-class metric alongside reply rate.
The four types of candidate contact data
| Type | Survives a job change | Typical coverage | Best used for |
|---|---|---|---|
| Work email | No | High | Fast reach when tenure is stable |
| Personal email | Yes | Moderate | Long-term nurture and passive outreach |
| Direct mobile | Usually | Lower | Scarce roles, scheduling after consent |
| Social profile URL | Yes | Very high | Identity resolution and a second channel |
The ranking flips between sales and recruiting. A sales team can build a good motion on work emails alone. A recruiting team cannot, because the candidate who just moved is the candidate worth calling. Personal email is the single highest-value field in candidate contact data for exactly this reason.
Where the data actually comes from
Providers assemble candidate contact data from a handful of recognisable sources, and understanding the mix tells you where accuracy will be strong or weak.
- Public web and professional profiles. Excellent for identity, employment history and titles. Rarely contains direct contact details.
- Contributory networks. Users share address books in exchange for credits. This is where much personal email and mobile data originates, and coverage skews toward well-networked professionals.
- Pattern inference. Work emails derived from a company’s known format. Cheap, plentiful, and the main source of bounces when unverified.
- Licensed and partner data. Purchased sets, often strong in specific regions or industries and weak elsewhere.
- Live verification. Real-time checks performed at the moment you request a record, which is the difference between a guess and a confirmation.
Ask any vendor which of these dominates their mobile coverage in your target geographies. A provider strong on US enterprise software may be materially weaker on European healthcare or Asian manufacturing, and headline database counts never reveal that.
How to test candidate contact data before you buy
Never evaluate a provider on the sample list they choose. Run your own test, and structure it so the result is decision-grade.
- Build a 200-profile control list from a real requisition you are working, not a generic one. Include your hardest geography and your most niche function.
- Record match rate. What percentage returned any contact detail at all? This is the number that governs your funnel.
- Record field-level coverage separately. Personal email, work email and mobile should each be reported on their own. Blended coverage figures hide weak fields.
- Send a small verified batch — 50 addresses maximum — and measure the true bounce rate. Anything above 3% is a problem.
- Dial 20 mobiles manually. Count how many reach the named person rather than a switchboard, a wrong number, or a dead line.
- Divide total cost by usable contacts. Not by credits consumed. Cost per usable contact is the only comparable figure across vendors.
That final calculation frequently reverses the apparent ranking. A cheaper provider with 55% usable coverage costs more per hire than a pricier one at 85%. Our breakdown of tools ranked by cost per usable contact applies the same method across the wider market.
Verification, catch-alls and protecting your domain
Verification is not a nice-to-have. Mailbox providers treat bounce rates as a reputation signal, so sending to unverified candidate contact data damages every campaign that follows, including the ones on unrelated roles.
Three practical rules keep you safe. First, suppress anything a verifier returns as invalid rather than sending to it hopefully. Second, treat catch-all domains as a separate risk tier and either exclude them or cap them at a small share of any send. Third, re-verify anything older than 90 days, because a record that was accurate last quarter may not be now.
Underneath all of it, your sending infrastructure needs to be correct. See our setup guide for SPF, DKIM and DMARC before scaling volume on any new domain.
The legal layer: what applies to candidate contact data
Holding someone’s personal number and email creates obligations regardless of how you obtained them. The specifics vary by jurisdiction, but the following four regimes cover most recruiting activity.
GDPR and UK GDPR
Personal email addresses and mobile numbers are personal data whether they are business or private. Passive sourcing usually relies on legitimate interests under Article 6(1)(f), which requires a documented balancing test showing your hiring need does not override the individual’s rights. Because you obtained the data indirectly, Article 14 also requires you to tell the person where their data came from, within a reasonable period and at the latest when you first contact them. A one-line privacy notice link in your first message satisfies this cleanly.
CAN-SPAM
US recruiting email must carry accurate headers, a valid physical postal address and a functioning opt-out honoured within ten business days. The FTC compliance guide sets out the requirements, and penalties apply per message rather than per campaign.
TCPA and text messaging
This is the sharpest edge in candidate contact data. The TCPA requires prior express written consent before automated or pre-recorded calls and texts, with statutory damages of $500 to $1,500 per message and no cap on class size. Buying a mobile number gives you the number, never the consent. Use mobiles for manually dialled calls and for texting only after a candidate has opted in.
CCPA and CPRA
California residents have rights to know, delete and opt out of the sale or sharing of their personal information, and job applicants are expressly covered. The California Attorney General’s CCPA resource sets out the notice requirements. Practically, keep opt-in boxes unchecked by default and be able to delete a candidate record completely on request.
One vendor obligation cuts across all four regimes: sign a data processing agreement with every provider. Without one, you remain accountable for their handling of data you never touched.
Data hygiene and the decay problem
Business contact data decays at roughly 25–30% a year, and recruiting databases decay faster because job changes are the whole point of the exercise. A talent pool without a refresh policy is a liability disguised as an asset.
- Re-enrich quarterly for any pool you actively market to, and annually for cold archives.
- Store the source and date against every field, so you can answer a subject access request without a forensic exercise.
- Keep one global suppression list spanning recruiting and sales, since candidates do not distinguish between your departments.
- Deduplicate on a stable identifier such as a profile URL rather than on name and employer, which change constantly.
Most of this only holds if enriched records flow back into your system of record cleanly. Our guide to ATS integration covers the sync patterns that prevent duplicate candidate records and broken source-of-hire reporting.
Credits, seats and the real cost of coverage
Contact data is almost always metered, and the meters differ in ways that matter. Some providers charge for a lookup whether or not it returns anything. Others charge only for successful reveals. Mobile credits are usually priced separately and consumed far faster than expected once a team discovers them.
Three questions settle most of it. Do credits roll over or expire monthly? What happens on overage, and at what rate? Can unused mobile credits be reallocated to email? We unpack the common models in how credits, seats and overages really add up, and the same structures apply to recruiting plans.
Frequently asked questions about candidate contact data
Is it legal to use a candidate’s personal email?
Generally yes, with conditions. In the EU and UK you need a documented legitimate interest and must provide a privacy notice at first contact. In the US you must meet CAN-SPAM requirements including a working opt-out. In both cases, honour objections permanently across every requisition rather than just the current one.
What is a good contactable rate?
Aim for 80% or higher on your core geographies and functions. Between 65% and 80% is workable if you plan volume accordingly. Below 65%, your provider is quietly setting a ceiling on how many hires the team can make.
Should I text candidates?
Only after consent. Text achieves engagement rates email cannot approach, which is exactly why regulators police it closely. Use SMS for interview scheduling and follow-ups with candidates already in process, and never for cold approaches in the US.
How often should a talent pool be re-verified?
Quarterly for pools you actively contact, annually otherwise. Always re-verify before any campaign to a list older than 90 days, because the bounce damage from one stale send outlasts the campaign by months.
Do bigger databases mean better coverage?
Not for your roles. A 700-million-profile database and a 300-million-profile database can perform identically on a specific segment, or invert entirely. Only a controlled test on your own requisitions answers the question, which is why the buying checklist above starts there.
Coverage first, cleverness second
Teams spend months refining outreach copy while a quarter of their pipeline sits unreachable. Candidate contact data is the constraint that determines whether any of that work reaches a human being, and it is measurable, testable and fixable within a fortnight.
Measure contactability, verify before you send, document your lawful basis, and revisit the whole thing every quarter.
Read next
- Candidate sourcing — the funnel this data feeds.
- Passive candidate outreach — using personal email well.
- The buying checklist — 45 questions to ask any data vendor before signing.
- Cost per hire — where data spend shows up in the numbers.
ZenBee provides verified work and personal emails plus direct mobiles across 700M+ profiles, refreshed continuously to keep bounce rates low. Explore the ZenBee recruitment platform or compare credit allowances on pricing.