# Why Validating Phone Numbers Saves Your Business Money > Demonstrates how real-time validation reduces wasted spending on SMS and voice while improving deliverability and ROI. Published 2025-03-12, updated 2026-10-03 by Marcus Whelan. Canonical: https://checkthatphone.com/blog/validating-phone-numbers-saves-money Every text you send to a dead number still costs you money. SMS providers typically bill per message sent, not per message delivered, so an invalid, disconnected, or non-SMS-capable number is pure waste. One bad number is rounding error. A list with 10% bad numbers, sent monthly, is a recurring bill for messages no human ever reads. Validating before you send is how you stop paying for that. ## Where the money actually leaks ### SMS marketing campaigns Say you have a 100,000-number list and 15% of it is unreachable. That's 15,000 messages you pay for and nobody receives, on every send. Validation cleans the list first by checking line type and deactivation status and confirming the number can take a text, so you only send to numbers that can receive it. Landlines are the biggest single bucket: across all our lookups about 32% of numbers are non-mobile, and only about 7% of landlines we check are SMS-capable ([more on finding those](/blog/why-your-sms-campaign-is-silently-dropping-landlines-and-how-to-detect-text-enabled-ones)). ### Two-factor authentication OTP codes sent to invalid numbers do double damage: you eat the send cost and the user gets locked out and files a ticket. Real-time validation confirms the number is active and text-enabled before the code goes out, which cuts failures and the support load behind them. [Improving 2FA with phone validation](/blog/improve-2fa-phone-validation) goes deeper. ### Sales and outreach Cold calling and SMS prospecting burn rep time and budget on numbers that ring out or never existed. Validate first and your reps work a list of genuinely reachable people instead of a graveyard. ## Real-time data beats area-code guesswork Static databases and third-party lists fall apart the moment a number ports or a user relocates. CheckThatPhone runs a live carrier dip at lookup time for U.S. and Canadian numbers and returns: - Line type (`dipCarrierType`, plus `nanpType` from numbering-plan data) - Recent carrier deactivations (`deactivationDate`, within the last 45 days) - Carrier details and porting status (`dipCarrier`, `dipCarrierSubType`, `dipPorted`) - An SMS recommendation (`action`, `deliverable`, `smsEligible`) - GeoIP and timezone data [See the API documentation](/docs) for the full set of fields returned with each request. ## Gate every send on `action` The simplest integration is one rule: call the API before a message goes out, and only send when `action` is `"send"`. Anything else comes back as `"unsubscribe"`, with `reason` saying why: a non-mobile or non-SMS-capable line, a carrier deactivation in the last 45 days, a blacklist hit, or, if you enable the add-on, a TCPA litigator match. Failed lookups don't use credits. ## What a first validation pass tends to surface Beyond the dead numbers, a first pass over an existing list often shows patterns worth acting on: - Lead sources that send a disproportionate share of VoIP or landline numbers - Old numbers in your CRM that the carrier has since deactivated - Area-code targeting that doesn't match where your contacts actually are Group the results by lead source and by when each number was collected before you decide what to fix. For a whole list, the [bulk CSV uploader](/bulk-phone-validation) does this in one job, and the [contact list hygiene use case](/use-cases/contact-list-hygiene) walks through the workflow. ## Running the numbers Take 500,000 SMS a month at $0.0075 each (check your provider's current rate) with a 12% undeliverable rate. That's roughly $450 a month, about $5,400 a year, spent on messages that go nowhere. And that's SMS alone, before you count failed voice attempts and verification retries. Now the other side. If those 500,000 sends go to a 125,000-number list you message weekly, validating the list once costs about $125 on the 100K plan: $100 for the first 100,000 lookups and $0.001 each for the other 25,000 ([pricing](/pricing)). Validation removes the $450 line item by catching the bad numbers before the send, not after the bill. The math is weaker for a list you message once, so validate the lists you send to repeatedly first. ## Next step The pitch here is simple: a fraction of a cent per validation against a steady drip of wasted sends. CheckThatPhone's API validates U.S. and Canadian numbers in real time, flags line type, and surfaces the contact data you need to route smartly. [Read the API documentation](/docs) to wire validation into your messaging flow, or [explore pricing plans](/pricing) and start trimming the waste. --- CheckThatPhone is a phone validation API for US and Canada numbers: https://checkthatphone.com (docs: https://checkthatphone.com/docs.md, pricing: https://checkthatphone.com/pricing.md).