Phones and numbers
Device support, keeping your number, caller ID and emergency calls.
- Call forwarding and voicemail: the codes, the costs abroad and the security traps
How call forwarding and voicemail work on a mobile line: the standard GSM codes to set, check and cancel each type of divert, what forwarded calls and voicemail can cost when you travel, and how to lock voicemail against hijacking and account-takeover tricks.
- Emergency calls over VoIP, Wi-Fi calling and apps: what works and what does not
Can you call 112 or 911 over Wi-Fi calling, a VoIP line or a messaging app? How the rules differ in the EU and the US, how your location is sent, and how to stay safe.
- Is my phone unlocked? How to check, and how to get a carrier lock removed
How to tell whether your phone is locked to one operator, on iPhone and Android, what the rules on unlocking are in the UK, Canada, the US and the EU, and what to check before travelling or buying second-hand.
- Keeping your number: porting, caller ID and spoofing when you call over the internet
Your rights when moving a phone number to another provider in the EU and US, how VoIP services display your caller ID, and how networks fight spoofed numbers.
- Supported devices: what makes a phone work well (or badly) for internet calls
Why calling apps and Wi-Fi calling work on one phone and not another: operating system support, background limits on iOS and Android, carrier settings, Bluetooth headsets and older devices.
