SMS not sending

[Busy-G]

Hello, 

I've pretty much tried everything that I can find on the internet to fix this but nothing has worked.

I'm trying to send a SMS to a phone but it's not sending. I type the message and hit the send button. Very quickly 'Trouble sending. check options' is displayed below the message withe two options retry and and it's not sent.

Using another phone/O2 SIM a SMS can be sent without any problems to the recipients phone so I don't think the issue is there and I can send SMSs to different phones without any problems.

The number is not blocked on my phone. 

The same happens with RCS on or off.

I can't check the call centre number as I can't find it anywhere in the settings to verify. 

I've restarted my phone. Switched airplane mode on/off. Logged into a different network (like Vodafone) and then back to O2 to force a settings reset. Switched off RCS. 

Nothing is working.

(I'm sure there's other things I've tried!)

Nokia 8.5, Android 12, using the stock messages app.

Any help will be appreciated.

Thanks.

[MI5]

@Busy-G 

The blocking would have to be on the recipients phone, not yours.

[Busy-G · Accepted solution]

So I've figured out the problem. The SIM I was trying to send the SMS texts to originated from the Isle of Man. I did not know this... Texts to the Isle of Man are not included in my monthly allowance and I have a £0 cap on my account.

I have increased my cap and the texts are now sending and my account is being charged 20p each time I send a text... As simple as that!