From 2020/1 when track-and-trace sign in was required at venues and there was the possibility of individual Covid Passports being introduced I put O2 Classic 321 PAYG Sims with £10 credit in spare phones. These still have credit as rarely used.
From the phones sending a text Balance or BALANCE to 20202 has always failed, I suspect the same for other O2 short codes.
While using the phones a few days ago just within 180 days to keep every SIM live and retain the credit I looked at this and realised the phones were adding +44 so sending the short code +4420202. Hence the failure. What ever I tried I could not send just 20202.
Searching the internet I saw a suggestion to try +20202.
This worked and I received a reply detailing the SIM was 321 Classic BUT 55p was deducted from the SIM credit for what O2 clearly state should be a free SMS.
55p is the charge for an international SMS.
This could be charged for a contract SIM too depending on the contract.
I post this as a warning to others not to try putting '+' before the shortcode.
To check the balance keying
*#10# then ' call '
works returning the balance on screen without charge ( within the UK - never tried outside UK ).
