The price your SMS provider quotes per message is the smallest number in the whole equation. By the time a verification code has done its job — or failed to — it has cost you several times its sticker price. And a code sent to fraud costs you all of that for nothing.
The base rate is a range, not a number
A domestic OTP might cost a fraction of a cent. The same message to a premium international range can run $0.10 to $0.50 or more — a 50x to 100x swing decided entirely by the destination.
Most teams reason about OTP cost using the domestic number. Their actual exposure is set by the most expensive destination their form will accept, which is usually anywhere on Earth.
Retries and fallbacks stack
One verification rarely means one send. The code doesn't arrive, or arrives late, and the user hits "resend." A carrier delays delivery and your fallback logic fires a second SMS, then a voice call.
Each retry is another billable send at the destination's rate. A single frustrated user on an expensive route can quietly cost more than a hundred smooth domestic ones.
The cost you don't see on the invoice
A failed verification isn't just a wasted SMS. It's a signup that stalls, a login that fails, a support ticket that a human has to answer. The engineering time spent staring at delivery dashboards is real too.
These don't show up as SMS spend. They show up as churn and headcount, which are far more expensive than the message ever was.
How AIT changes the math
Take that per-send cost — base rate, retries, support drag — and multiply it by traffic that exists only to generate sends. That's SMS pumping. It targets premium ranges specifically because they carry the highest termination fees, which means it lands on the most expensive rows in your cost table.
A rounding error becomes a budget line. The expense that was too small to model is suddenly the one finance is asking about.
The cheapest OTP is the one you never send
Here's the asymmetry that makes this tractable: a blocked send costs nothing. No base rate, no retries, no support ticket, no fraud payout. Zero.
So the goal isn't to make each OTP cheaper. It's to not send the ones that were never going to verify anyone. A pre-send decision that filters impossible numbers, premium ranges, and abusive velocity before the message leaves — in single-digit milliseconds — turns your most expensive sends into free denials.
You can't negotiate your way to a cheaper premium route. You can decline to send down it.