Phone Number Lookup API: The Complete Comparison
Comparing Datagma, Lusha, Apollo, and Kaspr on phone number API coverage, pricing per credit, mobile-only filtering, rollover, and API access tiers.
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Introduction
If you’re using a tool like Captain Data, Clay, or Surfe and need to integrate a phone number lookup API, there are several criteria to consider. The most important are price and accuracy — and specifically whether the API returns genuine mobile numbers or inflates results with landlines.
In this article, you will find a complete comparison of the main phone number APIs to help you make the best choice.
Number of Mobile Phone Numbers Found by API
The first question: will the API actually find the numbers you need?
We purchased subscriptions to Lusha, Apollo, Kaspr, and Datagma and ran a controlled test. We scraped 400 random LinkedIn profiles using Captain Data’s “Search Sales Navigator Leads” template across three audiences:
- North America — Marketing & CEO roles, 51–200 employees, Software Development & Banking
- United Kingdom — same criteria
- India — Finance roles, 5,000–10,000 employees, Healthcare
We then enriched each file using each provider’s Captain Data integration and compared the results.
Key finding: Apollo says they deliver mobile phone numbers, but when you audit deeply, a significant portion turn out to be landlines. In one test on French C-level contacts, only 1 in 9 “mobile” numbers from Apollo was actually mobile — you paid 9× the correct price.
Price of Phone Number API: Comparison
Price per Credit and API Access
Not all providers offer API access on standard plans:
| Provider | API Access | Starting Price |
|---|---|---|
| Datagma | All plans | from $39/month |
| Apollo | All plans | from $49/month |
| Lusha | Enterprise only (Scale plan) | ~$7,000/year |
| Kaspr | Enterprise only (Custom plan) | ~$7,000/year |
For most teams, Lusha and Kaspr’s enterprise-only API pricing makes them impractical unless you have a very large budget.
Price per Phone Number
Pricing per credit (roughly per phone or enrichment action):
- Datagma — from $0.58/credit
- Kaspr — from $0.60/credit
- Lusha (Pro) — from $0.75/credit
- Apollo — from $2/phone (or $0.20 for add-on credits, but these do not roll over)
Ability to Filter Mobile-Only Numbers
This is a critical criterion often overlooked:
Datagma: All numbers delivered are certified mobile numbers. You pay only if we find a mobile number. No landlines, ever.
Apollo: Claims mobile-only, but as shown above, many returned numbers are landlines. No refund on incorrect deliveries.
Lusha & Kaspr: You can specify “phone numbers only” (including landlines), but you cannot force mobile-only. You will be charged for landlines — less valuable for direct outreach.
Kaspr note: Enabling “phone numbers only” mode in the API doubles the price per credit according to their own documentation.
Rollover of Credits
Rollover means unused credits carry over month to month as long as you maintain a subscription.
| Provider | Rollover | Notes |
|---|---|---|
| Datagma | ✅ Yes | Credits also survive account pauses |
| Lusha | ✅ Yes | Lost on subscription end |
| Kaspr | ✅ Yes | Lost on subscription end |
| Apollo | ❌ No | All unused credits expire at month end |
Apollo’s no-rollover policy means you must precisely predict your monthly usage — or lose what you paid for.
Account Pausing
What happens to your credits when you stop your subscription?
- Apollo, Kaspr, Lusha: Credits are lost immediately on cancellation
- Datagma: You can pause your account as many times as you want at symbolic fees. Credits wait for you when you reactivate.
Free Emails Included
Email addresses and phone numbers don’t have the same value, yet Lusha and Kaspr charge the same credit for both. Datagma and Apollo include significant email quotas:
- Datagma: 3,750 to 45,000 verified emails/month depending on plan
- Apollo: Up to 10,000 emails/month (marketed as “unlimited”)
- Lusha & Kaspr: One credit per email, same as phone
So Which Phone Number API Should You Choose?
| Factor | Datagma | Apollo | Lusha | Kaspr |
|---|---|---|---|---|
| API on all plans | ✅ | ✅ | ❌ | ❌ |
| Mobile-only guarantee | ✅ | ❌ | ❌ | ❌ |
| Credit rollover | ✅ | ❌ | ✅ | ✅ |
| Account pause | ✅ | ❌ | ❌ | ❌ |
| Emails included | ✅ | ✅ | ❌ | ❌ |
| Lowest monthly price | $39 | $49 | ~$580 | ~$580 |
Datagma is the best option for teams that need mobile-only phone numbers via API at an accessible price point, with credit flexibility and no enterprise contract required.
Apollo is a reasonable alternative if volume is low and you don’t mind occasional landlines in results.
Lusha and Kaspr make sense only if you need their specific search filters or LinkedIn Recruiter integration, and your budget supports enterprise pricing.