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Cannot send SMS

  • August 18, 2026
  • 2 Antworten
  • 13 Aufrufe
I
Besucher:in

Hi, I’m having an issue sending SMS from my O₂ number. Incoming SMS still work normally, but when I send an SMS, there is no error or warning and the message appears to send normally. However, the recipient never receives it. This happens consistently, including when trying to send to different numbers. I can make calls, receive calls, no issue there, just not send SMS.

I am a Samsung phone, and I checked that the message center number is correct (+491760000443).

 Is it possible to get some assistance on this?

2 Antworten

Joe Doe
Legende
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  • Joe DoeLegende
  • Legende
  • August 18, 2026

​@isilv Did you use / have a multicard?

Bin nur Kunde und versuche anderen nach bestem Gewissen zu helfen / I'm just a customer and try to help others as best I can
o2_Giulia
  • o2_GiuliaModeratorin
  • Moderatorin
  • August 18, 2026

Hello ​@isilv,

welcome to our o2 Community 😀 

There can be various reasons why the text messages aren't arriving.

I first checked whether there were any blocks on your number, but that is not the case.

Have you already restarted your smartphone?

Has it already been tested with multiple recipients, or is only a specific phone number affected?

Are you or the recipient located abroad?

You can check if there is a service outage at your location using the Live Check. 

On some smartphones, you can adjust the validity period for text messages. For example, if it is set to just one hour and the recipient has their phone turned off during that time, the message won't be delivered later on. It is recommended to set it to the maximum.

Best regards

Giulia

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I
Besucher:in
  • isilv
  • Autor
  • Besucher:in
  • August 19, 2026

Hi, thanks for your reply!

Yes, I have already restarted my smartphone, but unfortunately this did not resolve the issue. I cannot adjust the validity period on my phone (no option for it), so I assume that is also not the problem.

I tried with multiple recipients, also some located abroad, and the problem remains.

I do have multicard, could that be the issue? 

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