If you are on a Swisscom or M-Budget subscription, you can change to M-Budget One
. Just send an SMS message with the text MBUDGETONE to the number 444. You will receive the confirmation of the activation of the new plan via SMS. Link
Previously, if you were on Swisscom and wanted to port your number to M-Budget One, you had to transfer it first to a Swisscom prepaid number and from there to M-Budget. Not anymore.