Hi woodelf, are you able to pick up these instructions I've pasted from their website (if you are on their legacy plan it needs the next drop down menu)
Turning voicemail on/off
TalkTalk's 1571 home phone voicemail service answers calls when you're away from the phone or engaged on another call. You'll know you have a new message in your mailbox because of the interrupted or "stuttered" dial tone on the line.
Our standard Voicemail service is automatically activated when you sign up to our Fast, Faster Fibre or Fastest Ultra Fibre Optic Broadband plan. However, if you'd like to activate Voicemail Plus you will need to switch it on in My Account.
Voicemail - you can store up to 10 messages, each up to 2 minutes long. All for free.
Voicemail Plus - this includes extra storage, personalised greetings and remote access to your voicemail- also for free!
Activating Voicemail Plus:
You can turn on your Voicemail Plus service in My Account.
Select My Services from the toolbar
Then choose Manage home phone Boosts from the dropdown menu.
Click the box next to Voicemail Plus.
Then choose the Update button at the bottom of your screen.
Select Confirm to save your changes.
If you're on one of our legacy plans (Simply Broadband, Essentials TV or Plus TV), you can turn voicemail on or off as below using your touch tone phone: