Businesses looking to reduce SMS costs often overlook the simplest lever available: validating phone numbers before sending. This phone validation case study shows how one national financial services company cut its monthly messaging spend by 35% after integrating real-time number verification into its SMS pipeline — eliminating hundreds of thousands of wasted messages each month.
The Company
A national B2C financial services platform running SMS-based lead nurturing, transactional reminders, and customer engagement campaigns.
- Sending 3M+ SMS messages per month
- Using multiple vendors and regional shortcodes
- Struggling with delivery issues, undelivered messages, and billing disputes
- No phone validation prior to send — all numbers collected via web forms or 3rd-party partners
The Problem
Their SMS platform reported a 15-18% delivery failure rate. Messages were being sent to:
- Disconnected numbers
- Recycled or ported lines
- Landlines or VoIP numbers unable to receive SMS
- Numbers flagged by carriers as high risk
The company paid per attempt regardless of delivery success. With over three million messages a month, even a modest failure rate translated to significant waste.
The Solution
The company integrated the CheckThatPhone API as a pre-send filter, validating every phone number in real time before message delivery.
Each record received:
- Line type (mobile, landline, VoIP)
- Carrier name and status
- Portability status
- Deactivation or suspension indicator
- Deliverability score and action recommendation
Messages were only sent if the API returned action = send. The integration took less than a day using the API documentation.
The Results
After 60 days in production:
- SMS delivery success rate increased by 12.6%
- Message volume decreased by ~900,000 per month (filtered out unreachable contacts)
- Total messaging cost dropped by 35% across vendors
- No impact on conversion or engagement rates — those actually improved
They also uncovered:
- High volumes of VoIP numbers from certain lead sources
- Suspended numbers in their own CRM database
- Inaccurate area code targeting in past campaigns
Getting Started
Validating phone numbers before sending protects budgets, improves performance, and reduces metric noise. If your organization is looking to reduce SMS costs the way this company did, CheckThatPhone can help you filter invalid numbers, lower delivery failure expenses, and improve targeting and ROI.
Review the API documentation to see how the validation and action recommendation system works, or check our pricing plans to find the tier that matches your sending volume.