We call. We read the code.
They type it in.

With voice OTP, the code is delivered by a phone call instead of an SMS. With NaCaller Voice OTP, your server starts a verification with method "voice". We call the user's Indian mobile number and read a 6-digit code aloud, twice. The user types the code into your app, and your server sends it to the check endpoint to confirm it. The code is valid for 10 minutes and allows up to 5 attempts. The call carries only the code, with no marketing and no menu.

NaCaller Voice OTP is the second method in the Miss OTP API, with the same API key, credits dashboard and webhook. Your default path starts a verification as usual and asks the user to give a missed call. Under it, add a "Get a call instead" link that starts a verification for the same number with method "voice", then shows a 6-digit input. When the user submits the code, your server sends it to the check endpoint and treats a success as verified. It is one extra branch in your code, and users who can place a call never see it.

NaCaller Voice OTP costs between ₹0.55 and ₹0.70 per answered call, depending on the prepaid pack. The Voice 500 pack is ₹349 for 500 calls (₹0.70 each), and the Voice 50,000 pack is ₹27,499 for 50,000 calls (₹0.55 each). The price is per answered call, not per minute. GST is added.

No. NaCaller Voice OTP charges only for calls the user answers. A call that rings out, is declined, or reaches a switched-off phone costs you nothing, because the unanswered call costs us nothing either. You can safely offer a retry without paying for the attempts that never connected.

NaCaller Voice OTP reads the code in English, Hindi or Telugu. The call carries only a short line and the digits, spoken slowly and read twice, so a user can write them down or type them as they listen. If you need another Indian language, tell us which one.

NaCaller Voice OTP reads a 6-digit numeric code, twice on the same call. The verification is valid for 10 minutes from when your server starts it, and the user gets up to 5 attempts to type it correctly before the verification has to be restarted. Your server checks the code through the API, so the code never has to be stored or compared in your own code.

Not NaCaller Voice OTP, not yet. Entities regulated by RBI, SEBI or IRDAI, such as banks, NBFCs, brokers and insurers, have to place their service and transactional calls, including OTP calls, from TRAI's 1600-series numbers. NaCaller Voice OTP does not call from a 1600-series number today, so it is not suitable for those companies. Unregulated businesses such as marketplaces, delivery, edtech, SaaS and D2C apps can use it.

A NaCaller Voice OTP call is placed because the user asked for it on your screen, and it speaks only the verification code, with no offer, promotion or menu. That makes it a transactional call rather than a promotional one, and DND preferences are aimed at promotional calls. Keep it that way: trigger a call only from a user action such as tapping "Get a call instead", and never use the verification call to carry marketing. Promotional calling has separate rules.

Use both, in that order. A missed call with Miss OTP by NaCaller has no code for the user to type or be tricked into sharing, and it costs less per verification. NaCaller Voice OTP covers users who can't place an outgoing call or would rather receive one. Voice OTP costs ₹0.55–₹0.70 per answered call, against ₹0.10–₹0.20 per verified number for a missed call, so making missed call the default keeps most verifications on the cheaper path. Both run on the same API key and webhook.

Yes. NaCaller Voice OTP includes 5 free answered calls per account, so you can hear the call on your own phone and wire up the code check before buying a pack. These are real calls on the live line, not a simulator. After that, packs start at ₹349 for 500 calls.

About the same, and it is better to be honest about why. NaCaller Voice OTP still delivers a code, so like any OTP a user can be talked into reading it out to a scammer. It avoids some SMS weaknesses: nothing shows on the lock screen, and nothing sits in an inbox that other apps can read. It is not protected against a SIM-swapped number, and neither is SMS. For the lowest phishing risk, make the missed call the default, because that method has no code at all. Keep voice as the fallback, and add a second factor for payments or account recovery.