Following a Swiss Federal Supreme Court ruling, some telecom services are subject to the Swiss Money Laundering Act (AMLA). As a consequence, all corporate customers in Switzerland will see their access to these services blocked by Swiss telephony operators as of 29 June 2020.
From this date, therefore, it will not be possible for CERN fixed or mobile lines to call, amongst others, Swiss 090x numbers, some Swiss SMS/MMS Business Numbers or Swisscom Easypay/NATELPay. Note that this includes numbers used by Geneva Airport, a number of airlines (including Swiss Miles&More, Lufthansa and Alitalia) and some consulates.
If you are contacting any of these services on a regular basis via a CERN mobile or fixed line, you may want to check with them how to continue reaching them.