SMS is not received by the international recipients

Hello ​@siddharth2022,

at the beginning of this post, you noted that these were SMS messages sent directly from a banking app. Some banks block the sending of security codes, for example, to foreign phone numbers. In this case, you would need to contact the bank in question.

But in your case, it also seems to be just a normal text message, right?

Are you receiving an error message stating that the message was not delivered?

For international numbers the recipient's phone number should begin with 00 or +. For inda for example please dial 0091 or +91. Please check in your Message app wether the messages were sent with the correct international format. Otherwise they will not be delivered.

Best regards

Giulia

Hi ​@o2_Giulia 

Thank you for your response.

Yes, we’ve already tried and tested everything you mentioned — including both automatic and manually typed messages, using the correct international formats (with +91 and 0091), and even multiple message types. Unfortunately, none of them worked.

The strange part is that no error message was received, but the messages were still not delivered, and the charges were deducted, which makes it even more frustrating.

There’s also no blocking on the bank’s side — they confirmed they receive messages from Germany numbers sent via other providers. So it seems something is going wrong at the sending provider level.

Would appreciate it if you could investigate further from your side.

Best regards,

Siddharth

Hello ​@siddharth2022,

until now, SMS charges were only calculated for messages to 91... numbers without 00 or + in front. The phone number may have been shortened by your smartphone's software.

Please check whether you have the correct Short Message Service Center number + 491760000443 (for o2) saved on your smartphone. Otherwise, messages may not be delivered. If you need help with this, please let us know which smartphone you are using.

Best regards

Giulia

Hello ​@o2_Giulia ,

Thanks for your message.

Just to clarify:

1. I always send international messages using +91 or 00 prefixes. However, in the PDF statement provided by O2, the messages appear as being sent to 91… numbers — no plus or 00. So clearly, this shortening is happening after the message is sent, likely on O2’s backend. The same format shows for messages sent within Germany, and those work fine.
2. The SMS Service Center number +491760000443 is correctly saved on my device.
3. I’m using a new phone since last month, and this issue started on my previous phone, from which the ticket was originally raised — so the phone cannot be the root cause.

At this point, can you prove that the issue is on my side? Because all indicators show otherwise. Why not just test this yourself? I’m happy to provide a few Indian numbers, and I’m confident the messages won’t go through.

Looking forward to a solution beyond just being asked to “check my phone” again.

Best regards,

Siddharth

Hello ​@siddharth2022,

I'm sorry if you get the impression that we're not trying to help you. I can assure you, that's not our intention.

We currently have no reported network-related restrictions on sending text messages to India. The text messages are obviously being sent, so we can surely rule out any network-related restrictions on our end.

Even checking your SMS messages two years ago didn't yield any results. Therefore, we suspected that the messages are either not being sent correctly or are being blocked on the recipient's end because the recipients have restrictions or blocks on receiving text messages. Have you asked the recipients about this as well?

We can of course submit another technical issue report for our network team. Please let us know if you can provide us with one or two recent examples (no older than four days). I will contact you again via private message then.

I understand that it is not satisfactory for you that we haven't found a solution yet, but I hope that we can get to the bottom of the problem and hopefully find a solution soon.

Best regards

Giulia

Hello ​@o2_Giulia 

To be honest, I’m quite frustrated with this back and forth. I understand you’re trying to help, but I’ve already explained that I don’t have any recent examples to share—because generating one would mean paying again for a test that has failed multiple times.

Yes, it’s “just 29 cents”, but if I have to keep paying every time to help your technical team investigate, maybe O2 could consider providing a small test balance for this purpose?

As I already mentioned, messages sent via O2 postpaid connections reach India, while prepaid ones consistently fail—for reasons still unclear to me. I suggest your technical team conducts the test from their side instead of asking me to spend more.

Regards,

Siddharth

Hello ​@siddharth2022 

I've contacted our technical support again to ask how we can resolve the issue.

I'm very sorry, but we can't determine why the SMS aren't arriving. We also have no way of verifying whether the SMS is being received or not. The text messages are sent properly over our network (and are therefore billed accordingly). We haven't been able to identify any errors on our side. Therefore, our support suspects that there may be a problem on the recipient's side.

I know this isn't the answer you were hoping for, and I'm sorry I can't offer you a solution.

Best regards

Giulia