Due to UK/EU anti-fraud regulations (PSD2), O2 requires a verified identity for international calling. If you bought a SIM from a vending machine, international calling is blocked until you register your ID online or in-store. You aren't removing a technical bar; you are removing a KYC (Know Your Customer) hold.
To International Call Barring (All outgoing international calls): #33*[PIN]# (Send) how to remove international call barring - o2
If the generic codes fail, O2 uses a specific "Network Service Code" for International calls. Try: ##21*[Password]# (Send) – Note: 21 diverts all calls; for barring specifically, you need 331 . Due to UK/EU anti-fraud regulations (PSD2), O2 requires
To remove it, you aren't just changing a toggle; you are explicitly assuming financial liability. Most people don't know that O2 adheres to the GSMA (GSM Association) standard for call barring. You don't need an app or a web portal; you need the SIM application toolkit hidden in your dialer. Most people don't know that O2 adheres to
Wait, what PIN? Unlike your SIM PIN (which unlocks the phone), Call Barring has a . On O2 UK, the default is usually 0000 or 1919 . On O2 Germany (Telefónica), it is often a 4-digit code provided when you bought the SIM. If you enter the wrong code three times, you lock the feature.
You must call O2 Customer Service. When you do, do not say "I want to remove international barring." Say: "I need you to audit the SS7 barring flags on my HLR profile for 'OCB' (Outgoing Call Barring - International). Please hard reset the T-Code 33 for my MSISDN." Support agents recognize this language. It tells them you know the infrastructure. They will likely push a "Network Reset" SMS to your phone. Open that SMS (it often contains **21* codes) and let it run. Your phone will reboot, and the borders will fall. Now that you have removed the barring, you are exposed. International rates on O2 can be ruinous—up to £2.00 per minute to Australia or the US if you don't have a bolt-on.
Call barring is controlled by specific codes. Here is the cheat sheet for international outgoing calls (code 10 or 1 depending on the handset, but typically 10 for all international except home country).