Most businesses discover their real OTP cost only after the first invoice arrives. The quoted rate looked small, but the final bill had GST on top, a registration fee nobody mentioned and a few charges for messages that never reached anyone. A little arithmetic before you sign can save you from that surprise.
This walkthrough uses the figures on the OTP SMS pricing in India page from MetaReach Marketing. Follow the steps below and you will have a realistic monthly estimate in a few minutes.
Step 1: Count Your OTPs, Not Your Users
Start with how many codes you will send in a month. A single user can trigger several, for example one at sign-up, one at each login and one more if they ask for a resend. Multiply your expected sign-ins and transactions by the average codes per action. Be generous, because resends and retries add up.
Step 2: Find Your Slab
Rates fall as your monthly volume grows. At MetaReach, the per-OTP rate depends on how many OTPs are delivered in the month, and all figures exclude 18% GST:
- Starter: ₹0.40 for 5,000 to 9,999 a month
- Growth: ₹0.30 to ₹0.20 for 10,000 to 49,999 a month
- Enterprise: ₹0.15 to ₹0.12 for 50,000 to 5,00,000 a month
Volumes below 5,000 or above 5 lakh are quoted individually. Volume discounts apply automatically, and there are no setup fees or contracts.
Step 3: Do the Sum, Then Add GST
Multiply your delivered OTPs by the slab rate, then add 18% GST. The page gives three handy examples:
- 10,000 OTPs at ₹0.30 comes to ₹3,000 plus ₹540 GST, so ₹3,540
- 50,000 OTPs at ₹0.15 comes to ₹7,500 plus ₹1,350 GST, so ₹8,850
- 1,00,000 OTPs at ₹0.12 comes to ₹12,000 plus ₹2,160 GST, so ₹14,160
Step 4: Remember You Pay for Delivery
Here is the part that makes OTP pricing friendlier than it first looks. You are billed only when an OTP is confirmed delivered to the handset. Unreachable or switched-off numbers, invalid numbers, operator rejections and intermediate retries are not charged. Pending messages with no delivery receipt inside the timeout are not charged either, unless a late receipt later confirms delivery. So your estimate should be based on delivered messages, which may be a little lower than the messages you send.
Step 5: Check for Extras
Some costs sit outside the per-OTP rate, and it helps to know them in advance:
- API and sandbox: API calls, sandbox calls and webhook callbacks are not charged separately.
- Voice OTP fallback: this is billed per call and depends on retries, call volume and language. English and Hindi are included at the base price, regional-language recordings may carry a setup fee and no exact rate is published, so ask for a quote.
- SMPP: high-volume connectivity may involve a one-time infrastructure setup discussion.
Step 6: Add the One-Time DLT Cost
DLT registration is mandatory for commercial SMS senders in India. The operator’s one-time entity registration fee is ₹5,900, which is ₹5,000 plus 18% GST, and it applies whichever provider you choose. MetaReach says it does not add its own handling fee, and that sender ID and OTP template approval are included. Register OTP templates under the category that fits your entity and use case, because a mismatch can cause rejections.
A Worked Example
Say an online store expects about 20,000 delivered OTPs a month. That sits in the Growth range, so the rate falls between ₹0.30 and ₹0.20, depending on the exact slab confirmed in the quote. At ₹0.20, the monthly cost is ₹4,000 plus ₹720 GST, which is ₹4,720. Add the one-time ₹5,900 DLT fee in the first month, and you have a clear starting budget.
What About Speed?
Price is only half the story. The provider describes delivery in roughly 3 to 5 seconds on priority routes, but that is not contractually guaranteed on the lower plans. A written SLA is available on request for Enterprise. If a slow code would cost you a sale, ask about speed before you decide, and test on your own numbers.
Common Mistakes to Avoid
Three slips cause most bill shocks. People forget GST, forget the one-time DLT fee and forget that resends count as extra messages. Add a small buffer to your estimate, and revisit it each quarter as your volume grows and a better slab comes into reach.