How do I set up and manage voicemail on a mobile?

Voicemail predates the smartphone by decades and has never been absorbed into it. It runs on your network's equipment, not on your phone, which is why the settings live behind dialled short codes rather than in a settings menu, why a new phone inherits your old greeting, and why nothing in the phone's help explains any of it. Two things follow. First, most voicemail problems are network problems and no amount of restarting the phone touches them. Second, the details — the access number, the codes to turn diversion on and off, whether retrieval is free — are network-specific and change, so the reliable source is always your own network's help pages rather than general advice.

Step by step

1. Call your voicemail and set it up on the first visit.121 reaches voicemail on most UK networks from your own phone, and the first call runs a setup sequence: record a name, record or choose a greeting, and set a PIN. Doing this deliberately is worth five minutes, because the default greeting tells callers nothing.
2. Record a greeting that gives people something to work with.Your name and one useful instruction. "You've reached Sam, please text me instead" saves more time than a longer message, because most people would rather text and are waiting to be told it is acceptable.
3. Set a PIN and know what it protects.The PIN stops your voicemail being retrieved from another phone. Default PINs were a genuine security problem historically, and networks now generally require one to be set. Choose something that is not your birth year, and store it in your password manager rather than in a note on the phone.
4. Decide whether you want visual voicemail.It lists messages on screen with a transcript on some networks, so you can read rather than listen and pick messages out of order. It works on both platforms with supporting networks and it makes voicemail considerably less unpleasant. It is worth asking your network whether it is included.
5. Understand the difference between diverting and switching off.Unanswered calls reach voicemail because your network diverts them there. Turning voicemail off means cancelling those diversions with a short code, which the network publishes. There are usually separate diversions for unanswered, busy and unreachable, and cancelling only one leaves the others working.
6. Change how long the phone rings before diverting.The ring time before voicemail picks up is a network setting, adjustable with a short code on most networks and often set to a rather short default. Lengthening it means fewer calls go to voicemail when the phone is in a bag.
7. Check whether retrieving messages is free.On many plans calls to voicemail are included, and on some pay-as-you-go plans they are not. If you rarely use it and it is not included, that is a further argument for turning it off or for using visual voicemail, which fetches messages over data instead.
8. Reset the greeting when you change phones or networks.The greeting lives on the network, so a new phone keeps the old one and a new network starts blank. Switching network is the moment to set it up again, and it is easy to forget for months.

Common mistakes

• Leaving the default greeting for years — Callers cannot tell they reached the right person, which means genuine callers hang up while nuisance callers do not care either way.
• Storing the voicemail PIN in a note on the phone — The PIN exists to protect your messages from someone who has your phone. A note on the same phone defeats it entirely.
• Assuming voicemail settings live on the handset — They do not, which is why a factory reset, a new phone or a reinstalled app changes nothing. The service is on the network and the settings are reached by dialling.

If it doesn't work

Questions people ask