Engage Product Updates

Improve your messaging delivery and reduce costs with number validation for Sinch Engage.

Before you hit send, know your list is clean. Sinch Engage now lets you verify whether a number is active and able to receive SMS — cutting wasted spend and keeping your campaigns focused on contacts who can actually hear from you.

You’ve spent time crafting the perfect SMS campaign. You hit send, but a chunk of your messages never arrive because the numbers are landlines, disconnected, or incorrectly formatted. This doesn’t just waste your budget—it can also hurt your sender reputation with carriers.

Ensuring your contact list is clean shouldn’t be a manual chore. That’s why we’ve brought the power of our real-time lookup technology directly into the Sinch Engage platform.

The Sinch Engage number validation page showing a campaign with 1,000 messages sent and 150 failed, next to a person in glasses holding a phone and benefit cards for reducing SMS waste, improving deliverability, and staying compliant

What we shipped

Real-time status checks. You can now verify if a phone number is currently active and assigned to a subscriber. This prevents you from sending to dead air and helps keep your bounce rates low.

Line type identification. Not every phone is a mobile phone. Our validation tool identifies whether a number is mobile, landline, VoIP, or unknown — so you can filter out the numbers that can’t receive SMS before you pay to send a single message.

Carrier data access. Gain insight into which carrier owns the number, which is critical for staying compliant with specific carrier regulations and optimizing delivery routes.

A number validation summary showing 72,140 messages sent with 10,790 failed to deliver over the last 30 days, above a button to find contacts to unsubscribe

How it works

Number validation is built directly into your contact management workflow. You can upload a new list or trigger a validation check when viewing a campaign report. The system cross-references the number with global carrier databases to return the most accurate, up-to-date status in seconds.

Why this matters

  • Higher ROI: Stop paying for messages that can’t be delivered. Every lookup ensures your budget goes to contacts you can actually reach.
  • Better deliverability: Removing invalid numbers from your list means fewer failed sends, which helps protect your sender reputation with carriers over time.
  • Stay compliant: Avoid sending to landlines without proper consent and reduce your exposure to TCPA violations, which can carry fines of $500–$1,500 per incident.

Get started

Run a validation check on any number at any time — individually or in bulk via CSV upload. Sinch Engage cross-references each number against carrier databases to return the line type, carrier, and current status in seconds. Results are stored in your lookup history for 60 days so you can revisit and act on them at any time.

Frequently Asked Questions

Q: What is number validation?
A: Number validation checks whether a phone number is active, reachable, and capable of receiving SMS. It identifies the line type (mobile, landline, VoIP, or unknown) and the current carrier — so you know exactly what’s on your list before you send.

Q: Can it detect landlines?
A: Yes. Every number is classified as mobile, landline, VoIP, or unknown — so you have a clear picture of what’s on your list before you send. You can use that data to filter out numbers that can’t receive SMS, avoiding wasted spend on undeliverable messages.

Q: Does it cost extra?
A: Yes, validation is charged at a flat rate of $0.008 per lookup on top of your existing plan. You only pay for the lookups you run.

Q: How often should I validate my list?
A: We recommend validating new contacts at the point of import. For existing lists, a periodic refresh is good practice — especially if your list hasn’t been updated in a while or you’re seeing higher than usual failed message rates.

Q: Does this work globally?
A: Number validation is currently available for US customers.