Third-Party Data: A Recruiter's Guide to Uses, Limits, and Rules

Recruiters encounter third-party data when a tool fills in a missing email, suggests a phone number, or adds company details to a profile. Most explanations online are written for marketers, but the same category covers much of the contact and profile data sold to recruiting teams.

Third-party data is information about people or companies collected by an organization with no direct relationship to them, then sold or licensed to others.

For recruiters, it includes bought contact lists, enriched emails and phone numbers, aggregated profiles, company data, and background check reports. It can help you reach people you'd otherwise miss, but you should check its accuracy, origin, and legal status before using it on candidates.

What is third-party data?

Third-party data is gathered by aggregators, data brokers, and enrichment providers, who compile records from public sources and partner feeds and then sell access. The collector has never dealt with the person in the record, which separates this category from data you or a partner gathered directly.

In recruiting, the most familiar form is contact data, such as a personal email, a mobile number, or a current job title. Providers also sell aggregated profiles with career history and inferred skills, plus company records on size, location, and technology. Background check reports belong here too, because a reporting company compiles them from records the candidate didn't hand you. The common thread is distance: the collector can't tell you whether an email is the one someone reads or whether a skill was stated or guessed.

First-party data vs third-party data, and the types in between

First-party data is what you collect yourself in your applicant tracking system (ATS), candidate relationship management (CRM) tool, careers site, and conversations.

Third-party data comes from an outside collector with no relationship to the person, and zero-party and second-party data sit on either side of that divide. The table compares all four by who collects the data, what it looks like in recruiting, and where each one helps or falls short.

A pay expectation a candidate gave you last month says more than an inferred salary band, and your own call notes show when you learned something. Zero-party data is the strongest of the four for intent, but it depends on asking good questions and recording the answers.

For agencies, records a client shares can fall under second-party terms. Check what your agreement allows before you add them to your own database.

How recruiters use third-party data

Recruiters use bought data mainly to reach people they don't have records for and to fill gaps in records they already hold. Most of these uses come down to data enrichment, which adds outside fields to an existing record, or list buying, which brings in new records.

• Finding contact details: Once you've identified someone through a public profile, a conference talk, or a referral, enrichment tools can suggest a work email or phone number. You still need to check suggestions, because usable contact data depends on how recently someone verified it.
• Enriching CRM records: Adding missing titles or employers can make an older database searchable again. It's worth limiting CRM data enrichment to the fields you'd act on, since every extra field is one more thing to keep current.
• Company research for business development: Agency recruiters use firmographic data such as company size, location, and growth to decide which employers to approach as clients. In-house teams use the same records to see where people with relevant experience work.
• Signals about hiring or company changes: Some providers flag funding rounds, leadership changes, or rising job postings. Treat intent data as a reason to look closer, not proof of a hiring need, to keep your outreach tied to what you can see.
• Background checks: Employers order reports from background reporting companies to confirm parts of a candidate's history before an offer. These reports follow their own legal rules, covered below.

Where bought data falls short

Bought data can be out of date, unclear in origin, or wrong in ways that are hard to spot. People change jobs and stop checking old email addresses, while a record reflects whatever the collector saw last. Without a date on each field, you can't tell a current email from one that stopped working long ago.

Origin and consent are harder to judge, because a record may come from public pages, partner feeds, or other brokers without the person knowing. Sources can also disagree, listing two employers for the same person. Inferred fields add another layer, since a seniority level guessed from a job title can be wrong and may not be marked as a guess.

Candidate trust can suffer as well. Someone contacted on a personal number they never shared with you may wonder how you got it, and that first impression can shape the conversation. Mentioning how you found the person, such as a public talk, gives them context.

Consider an agency recruiter who buys enriched contact details for a list of engineers. Several emails bounce, and some people on the list have since changed employers. The recruiter starts confirming contact details and current roles in the first conversation. From then on, the working record holds only what each person confirms.

Legal points to check before you use candidate data

Privacy and consumer reporting rules can apply when you use bought candidate data, depending on where your business operates and where candidates live. The points below describe what California and federal sources say, not how they apply to any one firm.

The California Consumer Privacy Act (CCPA) applies to covered businesses, not to every recruiter. California's privacy agency says the law covers California residents who are job applicants and that the employment data exemption expired at the end of 2022. If your business is covered, that can include candidate records you bought as well as ones you collected.

California also runs the Delete Request and Opt-Out Platform (DROP), where residents can ask registered data brokers to delete their data in one request. An agency announcement says that from August 1, 2026, brokers must check the DROP at least every 45 days and delete associated data, inferences included. That means records you bought from a registered broker may be deleted at the source unless an exemption applies. Whether your own firm counts as a data broker depends on how it collects and shares data, which is a question for counsel.

Background reports are subject to separate federal rules under the Fair Credit Reporting Act (FCRA). The Federal Trade Commission says employers need written permission before running a check through a background reporting company. Employers must also take certain steps, including giving the person a copy of the report, before deciding not to hire someone because of it.

Background verification software that records consent can help you track those steps. Other states add their own laws, so check with counsel on which rules apply to your desk.

How to judge third-party data providers

A practical way to judge a provider is to ask how it collects records and keeps them current, then test a sample against records you can verify.

• Origin and consent: Ask where the records come from and how the provider handles consent for personal contact details. A clear answer helps you explain to a candidate how you found them.
• Refresh and dates: Find out how often records are refreshed and whether each field shows when it was last confirmed. Dated fields tell you which details to check first.
• Match and accuracy testing: Request a sample for people and companies you already know, then compare. Note wrong employers, dead emails, and fields that were inferred rather than stated.
• Deletion and opt-out handling: Ask how the provider processes deletion requests, including DROP requests if it's a registered broker. Also ask whether it tells customers when it deletes a record.
• Compliance terms: Read what the contract says about permitted uses, your own obligations, and data broker registration where it applies.
• Integration with your ATS or CRM: Check whether records arrive with source labels, so your team can tell bought fields from confirmed ones. If you'd pull records through a person data API, ask which fields each call returns.
• Pricing and usage limits: Weigh credit, seat, and per-record pricing against how often you'd use the data, with the same scrutiny you'd apply when buying a list.

For the sample test, pick people you've spoken with recently and companies you know well, so you can judge each field against what you've heard firsthand. A provider that does well on your roles and regions may suit you better than one with a larger database.

How to build more first-party and zero-party data

You build first-party and zero-party data by asking candidates directly, recording what they tell you with their consent, and keeping those records current. Questions about preferred contact channel, availability, and pay expectations take little time in a screening call, and the answers come with a date and a clear origin.

A steady candidate relationship management routine keeps those details in use between searches, and bought data still has a place. Treat each bought record as a lead to verify and use it to fill gaps, such as a way to reach someone. Then confirm the details with the person and move what they confirm into your own records.

Labeling each field by source and date shows your team which details came from the candidate and which still need a check. Good talent pool management adds periodic reviews to update roles and remove people who asked not to be contacted. Agency recruiters who share profiles with clients should also note what each candidate agreed to share.

Check where your candidate data comes from before you buy more

Bought records can help you find people and companies you'd otherwise miss, but their value depends on knowing who collected them, when, and on what terms. California's privacy rules and federal background check law both turn on where a record came from and what the person agreed to. Before your next purchase or renewal, run a sample of records you can verify and ask the provider how it handles deletion requests.