In short
Start by asking who is failing. When no bank or app can reach you, the fault sits with your own handset or SIM: confirm you have signal and a valid recharge, open the spam or “Unknown Senders” folder, choose the correct SIM for SMS and reboot. When just one bank or app fails, that sender is usually to blame, so request the code by voice call or email instead.
Jump to a section11 sections
- Work out whose side the fault is on
- Step 1: Rule out the number, the signal and the SIM
- Step 2: Confirm your recharge hasn’t lapsed
- Step 3: Dig the OTP out of spam or filtered folders
- Step 4: Sort out dual-SIM mix-ups
- Step 5: Clear space and empty the SMS app’s cache
- Step 6: Review your DND preference
- Step 7: If the fault lies with the sender
- Still nothing? Ring your operator
- Common OTP questions
- Sources and further reading
Work out whose side the fault is on
Answer two things before you change any setting: do ordinary texts still reach you, and is every sender failing or only one? The table sends you to the right step.
| Symptom | Probable cause | Go to |
|---|---|---|
| Ordinary texts are missing too, and no bank or app OTP turns up | Network signal, the SIM, an expired plan or a phone setting | Step 1 and Step 2 |
| Regular SMS come through, yet every OTP is missing | A spam or unknown-sender filter, the SMS app itself, or DND | Step 3 to Step 6 |
| Only a single bank or app fails to deliver | A problem with how that sender sends its SMS | Step 7 |
The steps run from quickest to slowest. The first couple take less than a minute and clear up most cases, so go through them in order.
Shop-floor note: When customers bring this problem to Mobivault, it usually comes down to one of two things: a prepaid recharge that has lapsed, which can cut off incoming SMS, or an OTP that was in fact delivered but got sorted into the spam or unknown-senders folder. Rule out both before you try anything else.
Step 1: Rule out the number, the signal and the SIM
- Confirm which mobile number the bank or app holds for you. A single mistyped digit, or a number you stopped using, is a frequent culprit.
- Check that the phone shows network bars. To force a fresh connection, switch on Airplane mode, wait 10 seconds and switch it off again.
- Reboot, then ask for the OTP once more. Give it at least 2 minutes before you tap resend, because many apps cancel the earlier code as soon as a fresh one is requested.
- No luck yet? Move the SIM into a different handset and request the code there. If it shows up, your own phone’s settings are the issue (Step 3 to Step 5). If it doesn’t, look at the SIM, the plan or the sender.
Step 2: Confirm your recharge hasn’t lapsed
Once a prepaid pack’s validity runs out, an operator may cut off some services. How incoming SMS are treated after that is not the same across Jio, Airtel, Vi and BSNL, and it can also vary from circle to circle. Look up your validity in the operator’s own app: MyJio, Airtel Thanks, the Vi app or BSNL Selfcare. Operators often text you the date until which incoming services will keep running, so search your inbox for that message.
If a number exists mostly to receive bank OTPs, don’t let it lapse; a small recharge is enough. TRAI notified its Telecom Consumers Protection (Thirteenth Amendment) Regulations, 2026 on 22 September 2026. They oblige operators to sell a voice-and-SMS-only pack alongside each data bundle they offer with a validity of 30 days or less, along with a pack that renews on the same date every month. The rules apply 30 days after publication, so see what your operator’s app lists today.
Step 3: Dig the OTP out of spam or filtered folders
Messaging apps sort incoming texts on their own these days, and now and then a genuine OTP gets filed in the wrong spot.
Google Messages on Android
- In Messages, tap your profile picture (top right) and choose Spam & blocked. Found the OTP there? Open that chat and mark it as not spam.
- To review how the filter is set up, follow profile picture → Messages settings → Protection & Safety → Spam protection.
Samsung Messages on Galaxy phones
Go to Messages → ⋮ → Settings → Block numbers and spam and look through the blocked messages listed there.
Messages on iPhone
From iOS 26 onward, a feature called Screen Unknown Senders shifts texts from numbers you don’t know into their own Unknown Senders list. To search it, open Messages, tap the Filter button and pick Unknown Senders. Anyone using a text message filter should look under Transactions as well. The setting itself lives at Settings → Apps → Messages → Unknown Senders; there you can switch Screen Unknown Senders on or off and decide which alerts still reach you. According to Apple, alerts for time-sensitive texts like verification codes stay on by default. Had “Filter Unknown Senders” turned on in iOS 18? Then the new screening is enabled for you once you upgrade.
Tip: If Truecaller or a similar app handles your SMS by default, open its spam and block settings as well. Another option is to make the phone’s built-in Messages app the default for a minute, then ask for the OTP again.
Step 4: Sort out dual-SIM mix-ups
With two SIMs in one phone, the OTP is sent to whichever number the bank holds, regardless of the SIM you have set as default. Go into your phone’s SIM settings (brands label this differently, for example SIM manager or SIM cards & mobile networks) and make sure both SIMs are enabled and showing signal. If one of them keeps dropping off the network, disable the other SIM briefly and request the OTP again.
Bank and UPI apps verify your phone during setup by sending an SMS from it, so when the app asks you to choose a SIM, select the one whose number is registered with your bank.
Step 5: Clear space and empty the SMS app’s cache
When storage is full, a phone may be unable to save incoming texts. Remove old promotional SMS and any bulky files, and then, on Android, clear the cache of your Messages app:
- Go to Settings → Apps and locate the Messages app you use.
- Choose Storage and tap Clear cache.
- Reboot, then request a fresh OTP.
Warning: Use Clear cache only. The Clear data or Clear storage button can wipe the messages you have saved.
Step 6: Review your DND preference
Do Not Disturb (DND) exists to block promotional calls and SMS. TRAI’s rules keep transactional and service messages, OTPs included, outside its scope. Trouble starts when a business files its OTP template under the wrong category.
If your number is on full DND (FULLY BLOCK) and one particular sender’s OTPs never show up, move to BLOCK PROMO by texting it to 1909. TRAI’s 2025 rules spell out the difference: BLOCK PROMO stops promotional messages only, whereas FULLY BLOCK also blocks service messages that require your explicit consent. TRAI’s September 2026 amendment removes FULLY BLOCK altogether, and once it comes into force, operators will shift existing FULLY BLOCK registrations to BLOCK PROMO on their own. Calling 1909 and following the voice prompts works too, as do the TRAI DND app and your operator’s app. If that sender’s OTPs still don’t come through, request a voice call or email OTP from them (Step 7). Our guide on cutting down spam calls and SMS in India covers more ways to keep unwanted calls and texts away.
Step 7: If the fault lies with the sender
In India, every bank and app has to register each SMS template and its sender name (known as the “header”) with the telecom operators. A mistake in that registration can get their messages stopped before they land on anyone’s phone, and no setting on your handset can change that.
- Look at who the SMS is from. Since May 2025, operators have added a letter at the end of business SMS headers: -T means transactional, -S service, -G government and -P promotional. An OTP would normally carry a header ending in -T, and occasionally -S.
- Traceability is not the reason for delays, says TRAI. Its note of 19 December 2024 stated that the system runs “without compromising data security or delays in SMS delivery”. Messages pushed through unregistered routes have been rejected since 11 December 2024, which means a sender whose setup is broken may not get through at all.
- Use a different verification method. Most banks and apps let you receive the OTP by voice call or email, or approve the login inside their app. On the OTP screen, look for an option such as “Get OTP on call” or “Try another way”.
- Report it to the sender. Reach the bank’s or app’s support team and mention your operator. When only one sender’s OTPs fail, the fix has to come from them.
Still nothing? Ring your operator
If you have tried every step and no SMS of any kind are arriving, call your operator from the affected number and ask them to look into SMS service on your connection.
| Jio | Dial 199 for queries or 198 for complaints from a Jio number; 1800-889-9999 from any other network · MyJio app |
| Airtel | Dial 121 from an Airtel number; 198 (toll-free) for complaints · Airtel Thanks app |
| Vi | Dial 199 for queries or 198 for complaints from a Vi number · Vi app |
| BSNL | Dial 1503 from a BSNL number; 1800-180-1503 from any other network · BSNL Selfcare app |
Common OTP questions
Regular texts reach me but OTPs don’t. What is going on?
Your phone or SMS app may be filtering business messages. Look in the spam and unknown-sender folders (Step 3) and check your DND choice (Step 6). If just one bank or app is affected, the fault is on their end (Step 7).
Can DND stop OTPs from reaching me?
Usually not. TRAI’s rules exclude transactional and service messages such as OTPs from DND. A code can still be held back if the business filed it under the wrong category. Moving from FULLY BLOCK to BLOCK PROMO (by SMS to 1909), or asking the business for another way to verify, like a voice call or email OTP, generally sorts it out.
My recharge has run out. Can OTPs still reach me?
That varies by operator and by circle. Look in your operator’s app, or in the expiry SMS, for the date until which incoming services stay active, and keep a small plan running on any number you rely on for banking.
The code keeps going to a number I no longer use. How do I fix that?
Change the registered mobile number with the bank or app. Banks normally ask you to do this via net banking, an ATM or at a branch, since they won’t send an OTP to a number that isn’t in their records.
Sources and further reading
- Apple Support: seeing chats from unknown senders in iPhone Messages
- Google Messages Help: spam and blocked chats · How spam detection works
- TRAI Press Release No. 92/2024 on the SMS traceability framework
- TRAI: TCCCPR (Third Amendment) Regulations, 2026, which shift FULLY BLOCK users to BLOCK PROMO
- TRAI: registering your preferences (1909 by call or SMS, IVR, app or web)
- TRAI: Telecom Commercial Communications Customer Preference (Amendment) Regulations, 12 February 2025 (the 1909 options are set out in Schedule-II)
- MediaNama (July 2025): telcos add -P, -S, -T, -G suffixes to commercial message headers
Updated 10 October 2026: Step 6 now covers how BLOCK PROMO differs from FULLY BLOCK, the call and app routes for 1909, and TRAI’s September 2026 move to withdraw FULLY BLOCK.
