Phone validation for recruiting

Why recruiters need phone validation

Phone validation for recruiting solves a problem every talent acquisition team runs into: a candidate list full of numbers you cannot reliably reach. ATS databases collect phone numbers from job applications, LinkedIn sourcing, referrals, and resume imports — and none of those sources verify whether the number is active, what type of line it is, or whether it can receive an SMS.

Before your recruiter sends a text sequence or hands a list to a dialer, you need to know which numbers are mobile, which are landlines, and which are disconnected. Texting a landline fails silently. Calling a disconnected number burns dial time. Running your list through a validator before outreach takes under ten minutes and prevents both problems.

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  Send SMS outreach only to mobile numbers — the only line type that reliably receives texts.
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  Route landline numbers to a voice-only calling cadence so your team does not waste time on undeliverable texts.
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  Remove invalid and disconnected numbers from your outreach list entirely before paying per-send fees to your SMS or dialer platform.
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  Flag VOIP numbers — Google Voice, Skype, or business lines — so recruiters can note the contact type before reaching out to a candidate.

How stale phone data wastes recruiter time

Candidate phone numbers go stale faster than most recruiting teams expect. A number a candidate submitted 12 months ago may be disconnected, ported to a new carrier, or belong to someone else entirely. When a recruiter calls or texts that number, the result is wasted effort at best and a compliance risk at worst if the number has been reassigned.

The problem compounds in high-volume hiring. A team sourcing hundreds of candidates per week from job boards, LinkedIn, and referrals accumulates bad data quickly. Numbers entered on mobile forms are frequently mistyped. Numbers from purchased lists may be years old. Numbers pulled from passive candidate databases may predate the candidate's last phone upgrade.

Beyond wasted time, dialing or texting disconnected and reassigned numbers can trigger carrier flagging on your sending number. Carriers track complaint and failure rates. A recruiter's dedicated outreach number that generates too many failure signals can end up on spam lists, reducing answer rates on your good contacts.

How to validate candidate phone numbers

The process takes four steps and under ten minutes for most list sizes.

1. 1
   Export your candidate list as a CSV. From your ATS — Greenhouse, Lever, Workday, Bullhorn, or any platform that supports CSV export — pull the candidates you want to reach. Include the phone number column. Other columns (name, email, job title, stage) are preserved and returned with the results.
2. 2
   Upload to PhoneCheckr. Drop the CSV onto the upload area. PhoneCheckr detects the phone number column and runs each number against the national carrier database. A list of 1,000 candidates typically processes in under two minutes.
3. 3
   Download the enriched file. The result CSV includes your original data plus a Type column (mobile, landline, voip, or invalid) and a Carrier column for every candidate. Open it in Excel or Google Sheets.
4. 4
   Filter and route. Sort or filter the Type column. Remove invalid rows. Route landline numbers to a calling-only cadence. Flag VOIP numbers for recruiter review. Import mobile numbers into your SMS outreach tool or dialer as your primary contact segment.

Validation costs $0.01 per number — a list of 2,000 candidates costs $20. Upload your first list here.

Screening VOIP and landline numbers in applicant data

Not all phone numbers in your ATS are equal, and line type tells you more than just whether SMS will work.

Landline numbers in candidate records usually come from two places: candidates who entered a home or office number on a job application, and ATS imports that pulled contact data from older resume databases. Landlines cannot receive texts. If your recruiter is running an SMS-based outreach sequence, landline contacts should be moved to a separate calling cadence or flagged for manual outreach. See the carrier lookup tool if you need to check individual numbers by hand.

VOIP numbers in candidate records are common and do not automatically indicate a problem. Many candidates use Google Voice as a secondary contact number, or their employer issued them a VOIP business line. Some candidates also use VOIP numbers when they prefer not to give out their personal mobile. For more on what VOIP numbers are and how they behave differently from mobile lines, see what is a VOIP number. PhoneCheckr shows the specific carrier for every VOIP number — a Google Voice number and a Twilio number are both VOIP, but they represent different contact situations.

Invalid numbers are disconnected or unassigned. No channel reaches them. Removing invalid numbers from your list before outreach is the most direct way to reduce wasted effort and protect your sending reputation.

Mobile numbers from major carriers — AT&T, Verizon, T-Mobile — are your strongest contacts. They support both SMS and voice, the candidate is likely the direct owner of the number, and you can reach them on either channel depending on your outreach strategy.