It's certainly up and running for Voipfone users and has been for quite some time.
If you look hard enough, you will discover all these system wide short codes, there maybe more, so if my list is incomplete, then please mention it on this thread. There was some talk a while back about 888 (Personal safety when you can't speak) but I think that has fallen by the wayside.
112 Emergency Services
999 Emergency Services
101 Police Non-Emergency Number
111 NHS Mon-Emergency Number
105 Power Cut Information Line
116 999 Missing children helpline
116 111 NSPCC ChildLine
116 123 Samaritans
119 COVID-19 Help Line (Also used to make appointments)
123 Gives Day, Date and Time
141 Withhold your number (If you must – Not Recommended)
1470 Un-withhold your number
150 Voipfone Customer Services (Password protected service)
152 Echo test. Shows how good your connection to Voipfone is.
154 A recording of call credit left to use before top-up is necessary
155 Confirms that you have set up your phone correctly
159 Report a Banking Scam (See
https://stopscamsuk.org.uk/159)
166 Voipfone Anti-Sales call tool (Optional monthly fee payable)
118 797 Connects to BT's Directory Enquiry services (Very expensive to use)
1280 Carrier pre-select disconnect from Voipfone (Only available to BT subscribers with pre-registration required)
1471 Plays back the last incoming number
1571 Voicemail for the extension you are using
1572 Voicemail for the Master Account (Used where your account does not have extension numbers)
1573 Voicemail for Group messages (Input the Group Number of Interest)
1995 Music on Hold (Listen to what is playing now)
## Transfer the call (Example ##01252758123 and hang up - Call charges may apply)
#0 Stops and starts call recording (Charged at 2.5 ppm)
** Generally used in business environments (Example **205 for call pickup from that extension)